Smart surveillance camera systems and methods

ABSTRACT

Various techniques are disclosed for smart surveillance camera systems and methods using thermal imaging to intelligently control illumination and monitoring of a surveillance scene. For example, a smart camera system may include a thermal imager, an IR illuminator, a visible light illuminator, a visible/near IR (NIR) light camera, and a processor. The camera system may capture thermal images of the scene using the thermal imager, and analyze the thermal images to detect a presence and an attribute of an object in the scene. In response to the detection, various light sources may be selectively operated to illuminate the object only when needed or desired, with a suitable type of light source, with a suitable beam angle and width, or in otherwise desirable manner. The visible/NIR light camera may also be selectively operated based on the detection to capture or record surveillance images containing objects of interest.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. International PatentApplication No. PCT/US2012/058099 filed Sep. 28, 2012 and entitled“SMART SURVEILLANCE CAMERA SYSTEMS AND METHODS” which is herebyincorporated by reference in its entirety.

U.S. International Patent Application No. PCT/US2012/058099 claims thebenefit of U.S. Provisional Patent Application No. 61/545,056 filed Oct.7, 2011 and entitled “NON-UNIFORMITY CORRECTION TECHNIQUES FOR INFRAREDIMAGING DEVICES” which is hereby incorporated by reference in itsentirety.

U.S. International Patent Application No. PCT/US2012/058099 claims thebenefit of U.S. Provisional Patent Application No. 61/663,336 filed Jun.22, 2012 and entitled “SMART SURVEILLANCE CAMERA SYSTEMS AND METHODS”which is hereby incorporated by reference in its entirety.

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/099,818 filed Dec. 6, 2013 and entitled “NON-UNIFORMITYCORRECTION TECHNIQUES FOR INFRARED IMAGING DEVICES” which is herebyincorporated by reference in its entirety.

U.S. patent application Ser. No. 14/099,818 is a continuation ofInternational Patent Application No. PCT/US2012/041749 filed Jun. 8,2012 and entitled “NON-UNIFORMITY CORRECTION TECHNIQUES FOR INFRAREDIMAGING DEVICES” which is hereby incorporated by reference in itsentirety.

International Patent Application No. PCT/US2012/041749 claims thebenefit of U.S. Provisional Patent Application No. 61/545,056 filed Oct.7, 2011 and entitled “NON-UNIFORMITY CORRECTION TECHNIQUES FOR INFRAREDIMAGING DEVICES” which is hereby incorporated by reference in itsentirety.

International Patent Application No. PCT/US2012/041749 claims thebenefit of U.S. Provisional Patent Application No. 61/495,873 filed Jun.10, 2011 and entitled “INFRARED CAMERA PACKAGING SYSTEMS AND METHODS”which is hereby incorporated by reference in its entirety.

International Patent Application No. PCT/US2012/041749 claims thebenefit of U.S. Provisional Patent Application No. 61/495,879 filed Jun.10, 2011 and entitled “INFRARED CAMERA SYSTEM ARCHITECTURES” which ishereby incorporated by reference in its entirety.

International Patent Application No. PCT/US2012/041749 claims thebenefit of U.S. Provisional Patent Application No. 61/495,888 filed Jun.10, 2011 and entitled “INFRARED CAMERA CALIBRATION TECHNIQUES” which ishereby incorporated by reference in its entirety.

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/101,258 filed Dec. 9, 2013 and entitled “INFRARED CAMERASYSTEM ARCHITECTURES” which is hereby incorporated by reference in itsentirety.

U.S. patent application Ser. No. 14/101,258 is a continuation ofInternational Patent Application No. PCT/US2012/041739 filed Jun. 8,2012 and entitled “INFRARED CAMERA SYSTEM ARCHITECTURES” which is herebyincorporated by reference in its entirety.

International Patent Application No. PCT/US2012/041739 claims thebenefit of U.S. Provisional Patent Application No. 61/495,873 filed Jun.10, 2011 and entitled “INFRARED CAMERA PACKAGING SYSTEMS AND METHODS”which is hereby incorporated by reference in its entirety.

International Patent Application No. PCT/US2012/041739 claims thebenefit of U.S. Provisional Patent Application No. 61/495,879 filed Jun.10, 2011 and entitled “INFRARED CAMERA SYSTEM ARCHITECTURES” which ishereby incorporated by reference in its entirety.

International Patent Application No. PCT/US2012/041739 claims thebenefit of U.S. Provisional Patent Application No. 61/495,888 filed Jun.10, 2011 and entitled “INFRARED CAMERA CALIBRATION TECHNIQUES” which ishereby incorporated by reference in its entirety.

This patent application is a continuation-in-part of U.S. patentapplication Ser. No. 13/437,645 filed Apr. 2, 2012 and entitled“INFRARED RESOLUTION AND CONTRAST ENHANCEMENT WITH FUSION” which ishereby incorporated by reference in its entirety.

U.S. patent application Ser. No. 13/437,645 is a continuation-in-part ofU.S. patent application Ser. No. 13/105,765 filed May 11, 2011 andentitled “INFRARED RESOLUTION AND CONTRAST ENHANCEMENT WITH FUSION”which is hereby incorporated by reference in its entirety.

U.S. patent application Ser. No. 13/437,645 also claims the benefit ofU.S. Provisional Patent Application No. 61/473,207 filed Apr. 8, 2011and entitled “INFRARED RESOLUTION AND CONTRAST ENHANCEMENT WITH FUSION”which is hereby incorporated by reference in its entirety.

U.S. patent application Ser. No. 13/437,645 is also acontinuation-in-part of U.S. patent application Ser. No. 12/766,739filed Apr. 23, 2010 and entitled “INFRARED RESOLUTION AND CONTRASTENHANCEMENT WITH FUSION” which is hereby incorporated by reference inits entirety.

U.S. patent application Ser. No. 13/105,765 is a continuation ofInternational Patent Application No. PCT/EP2011/056,432 filed Apr. 21,2011 and entitled “INFRARED RESOLUTION AND CONTRAST ENHANCEMENT WITHFUSION” which is hereby incorporated by reference in its entirety.

U.S. patent application Ser. No. 13/105,765 is also acontinuation-in-part of U.S. patent application Ser. No. 12/766,739which is hereby incorporated by reference in its entirety.

International Patent Application No. PCT/EP2011/056432 is acontinuation-in-part of U.S. patent application Ser. No. 12/766,739which is hereby incorporated by reference in its entirety.

International Patent Application No. PCT/EP2011/056432 also claims thebenefit of U.S. Provisional Patent Application No. 61/473,207 which ishereby incorporated by reference in its entirety.

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/138,058 filed Dec. 21, 2013 and entitled “COMPACTMULTI-SPECTRUM IMAGING WITH FUSION” which is hereby incorporated byreference in its entirety.

U.S. patent application Ser. No. 14/138,058 claims the benefit of U.S.Provisional Patent Application No. 61/748,018 filed Dec. 31, 2012 andentitled “COMPACT MULTI-SPECTRUM IMAGING WITH FUSION” which is herebyincorporated by reference in its entirety.

This application is a continuation-in-part of U.S. patent applicationSer. No. 12/477,828 filed Jun. 3, 2009 and entitled “INFRARED CAMERASYSTEMS AND METHODS FOR DUAL to SENSOR APPLICATIONS” which is herebyincorporated by reference in its entirety.

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/138,040 filed Dec. 21, 2013 and entitled “TIME SPACEDINFRARED IMAGE ENHANCEMENT” which is hereby incorporated by reference inits entirety.

U.S. patent application Ser. No. 14/138,040 claims the benefit of U.S.Provisional Patent Application No. 61/792,582 filed Mar. 15, 2013 andentitled “TIME SPACED INFRARED IMAGE ENHANCEMENT” which is herebyincorporated by reference in its entirety.

U.S. patent application Ser. No. 14/138,040 also claims the benefit ofU.S. Provisional Patent Application No. 61/746,069 filed Dec. 26, 2012and entitled “TIME SPACED INFRARED IMAGE ENHANCEMENT” which is herebyincorporated by reference in its entirety.

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/138,052 filed Dec. 21, 2013 and entitled “INFRARED IMAGINGENHANCEMENT WITH FUSION” which is hereby incorporated by reference inits entirety.

U.S. patent application Ser. No. 14/138,052 claims the benefit of U.S.Provisional Patent Application No. 61/793,952 filed Mar. 15, 2013 andentitled “INFRARED IMAGING ENHANCEMENT WITH FUSION” which is herebyincorporated by reference in its entirety.

U.S. patent application Ser. No. 14/138,052 also claims the benefit ofU.S. Provisional Patent Application No. 61/746,074 filed Dec. 26, 2012and entitled “INFRARED IMAGING ENHANCEMENT WITH FUSION” which is herebyincorporated by reference in its entirety.

TECHNICAL FIELD

One or more embodiments of the invention relate generally to thermalimaging devices and more particularly, for example, to the use ofthermal images to intelligently control illumination and monitoringoperations of surveillance camera systems.

BACKGROUND

Many conventional cameras, such as surveillance cameras, use constantactive illumination by visible or infrared light sources. Unfortunately,such light sources may attract many types of insects which maysignificantly degrade the quality and ability of such cameras to provideuseful images of a scene. For example, spider webs may accumulate nearor on the front side of the cameras, and such spider webs may in turnattract and retain additional insects and/or debris. Thus, the qualityof surveillance images are often degraded due to obstruction andinterference by insects and spider webs. Even worse, the presence ormovement of these objects may be interpreted by surveillance camerasystems as movement and therefore cause certain systems, such asconventional video motion detection (VMD) systems, to continuerecording. For example, it is not uncommon to end up with long butmeaningless surveillance recordings of nothing but spider webs swingingin the wind, moths fluttering around, or spiders building webs. Suchproblems are exacerbated by the fact that many conventional camerasystems are not effective in discerning real objects of interest (e.g.,persons, vehicles) from spurious objects (e.g., insects or spider webs)or environmental changes (e.g., changes in lighting conditions, whetherconditions, or other changes in the background).

SUMMARY

Various techniques are disclosed for smart surveillance camera systemsand methods using thermal imaging to intelligently control illuminationand monitoring of a surveillance scene. For example, a smart camerasystem may include a thermal imager, an IR illuminator, a visible lightilluminator, a visible/near IR (NIR) light camera, and a processor. Thecamera system may capture thermal images of the scene using the thermalimager, and analyze the thermal images to detect a presence and anattribute of an object in the scene. In response to the detection,various light sources of the camera system may be selectively operatedto illuminate the object only when needed or desired, with a suitabletype of light source, with a suitable beam angle and width, or inotherwise desirable manner. The visible/NIR light camera may also beselectively operated based on the detection to capture or recordsurveillance images containing objects of interest.

In one embodiment, a camera system includes a thermal imager comprisinga focal plane array (FPA) configured to capture thermal images of ascene; a light source configured to illuminate the scene; a cameraconfigured to capture additional images of the scene; and a processorconfigured to analyze the thermal images to determine an attributeassociated with an object in the scene, and selectively operate thelight source and the camera based on the attribute of the object.

In another embodiment, a method includes capturing, at a focal planearray (FPA) of a thermal imager, thermal images of a scene; analyzingthe thermal images to determine an attribute associated with an objectin the scene; and selectively operating a light source and a camerabased on the attribute of the object, wherein the light source isconfigured to illuminate the scene, and the camera is configured tocapture additional images of the scene.

The scope of the invention is defined by the claims, which areincorporated into this section by reference. A more completeunderstanding of embodiments of the invention will be afforded to thoseskilled in the art, as well as a realization of additional advantagesthereof, by a consideration of the following detailed description of oneor more embodiments. Reference will be made to the appended sheets ofdrawings that will first be described briefly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an infrared imaging module configured to beimplemented in a host device in accordance with an embodiment of thedisclosure.

FIG. 2 illustrates an assembled infrared imaging module in accordancewith an embodiment of the disclosure.

FIG. 3 illustrates an exploded view of an infrared imaging modulejuxtaposed over a socket in accordance with an embodiment of thedisclosure.

FIG. 4 illustrates a block diagram of an infrared sensor assemblyincluding an array of infrared sensors in accordance with an embodimentof the disclosure.

FIG. 5 illustrates a flow diagram of various operations to determine NUCterms in accordance with an embodiment of the disclosure.

FIG. 6 illustrates differences between neighboring pixels in accordancewith an embodiment of the disclosure.

FIG. 7 illustrates a flat field correction technique in accordance withan embodiment of the disclosure.

FIG. 8 illustrates various image processing techniques of FIG. 5 andother operations applied in an image processing pipeline in accordancewith an embodiment of the disclosure.

FIG. 9 illustrates a temporal noise reduction process in accordance withan embodiment of the disclosure.

FIG. 10 illustrates particular implementation details of severalprocesses of the image processing pipeline of FIG. 6 in accordance withan embodiment of the disclosure.

FIG. 11 illustrates spatially correlated FPN in a neighborhood of pixelsin accordance with an embodiment of the disclosure.

FIG. 12 illustrates a block diagram of a smart surveillance camerasystem having a thermal imager in accordance with an embodiment of thedisclosure.

FIG. 13 illustrates a front view of a smart surveillance camera systemhaving a thermal imager in accordance with an embodiment of thedisclosure.

FIG. 14 illustrates a front view of a smart surveillance camera systemhaving a thermal imager in accordance with another embodiment of thedisclosure.

FIG. 15 illustrates a perspective view of a smart surveillance camerasystem implemented as a module that can be conveniently deployed inaccordance with an embodiment of the disclosure.

FIG. 16 illustrates a process to perform smart illumination andmonitoring of a surveillance scene in accordance with an embodiment ofthe disclosure.

Embodiments of the invention and their advantages are best understood byreferring to the detailed description that follows. It should beappreciated that like reference numerals are used to identify likeelements illustrated in one or more of the figures.

DETAILED DESCRIPTION

FIG. 1 illustrates an infrared imaging module 100 (e.g., an infraredcamera or an infrared imaging device) configured to be implemented in ahost device 102 in accordance with an embodiment of the disclosure.Infrared imaging module 100 may be implemented, for one or moreembodiments, with a small form factor and in accordance with wafer levelpackaging techniques or other packaging techniques.

In one embodiment, infrared imaging module 100 may be configured to beimplemented in a small portable host device 102, such as a mobiletelephone, a tablet computing device, a laptop computing device, apersonal digital assistant, a visible light camera, a music player, orany other appropriate mobile device. In this regard, infrared imagingmodule 100 may be used to provide infrared imaging features to hostdevice 102. For example, infrared imaging module 100 may be configuredto capture, process, and/or otherwise manage infrared images and providesuch infrared images to host device 102 for use in any desired fashion(e.g., for further processing, to store in memory, to display, to use byvarious applications running on host device 102, to export to otherdevices, or other uses).

In various embodiments, infrared imaging module 100 may be configured tooperate at low voltage levels and over a wide temperature range. Forexample, in one embodiment, infrared imaging module 100 may operateusing a power supply of approximately 2.4 volts, 2.5 volts, 2.8 volts,or lower voltages, and operate over a temperature range of approximately−20 degrees C. to approximately +60 degrees C. (e.g., providing asuitable dynamic range and performance over an environmental temperaturerange of approximately 80 degrees C.). In one embodiment, by operatinginfrared imaging module 100 at low voltage levels, infrared imagingmodule 100 may experience reduced amounts of self heating in comparisonwith other types of infrared imaging devices. As a result, infraredimaging module 100 may be operated with reduced measures to compensatefor such self heating.

As shown in FIG. 1, host device 102 may include a socket 104, a shutter105, motion sensors 194, a processor 195, a memory 196, a display 197,and/or other components 198. Socket 104 may be configured to receiveinfrared imaging module 100 as identified by arrow 101. In this regard,FIG. 2 illustrates infrared imaging module 100 assembled in socket 104in accordance with an embodiment of the disclosure.

Motion sensors 194 may be implemented by one or more accelerometers,gyroscopes, or other appropriate devices that may be used to detectmovement of host device 102. Motion sensors 194 may be monitored by andprovide information to processing module 160 or processor 195 to detectmotion. In various embodiments, motion sensors 194 may be implemented aspart of host device 102 (as shown in FIG. 1), infrared imaging module100, or other devices attached to or otherwise interfaced with hostdevice 102.

Processor 195 may be implemented as any appropriate processing device(e.g., logic device, microcontroller, processor, application specificintegrated circuit (ASIC), or other device) that may be used by hostdevice 102 to execute appropriate instructions, such as softwareinstructions provided in memory 196. Display 197 may be used to displaycaptured and/or processed infrared images and/or other images, data, andinformation. Other components 198 may be used to implement any featuresof host device 102 as may be desired for various applications (e.g.,clocks, temperature sensors, a visible light camera, or othercomponents). In addition, a machine readable medium 193 may be providedfor storing non-transitory instructions for loading into memory 196 andexecution by processor 195.

In various embodiments, infrared imaging module 100 and socket 104 maybe implemented for mass production to facilitate high volumeapplications, such as for implementation in mobile telephones or otherdevices (e.g., requiring small form factors). In one embodiment, thecombination of infrared imaging module 100 and socket 104 may exhibitoverall dimensions of approximately 8.5 mm by 8.5 mm by 5.9 mm whileinfrared imaging module 100 is installed in socket 104.

FIG. 3 illustrates an exploded view of infrared imaging module 100juxtaposed over socket 104 in accordance with an embodiment of thedisclosure. Infrared imaging module 100 may include a lens barrel 110, ahousing 120, an infrared sensor assembly 128, a circuit board 170, abase 150, and a processing module 160.

Lens barrel 110 may at least partially enclose an optical element 180(e.g., a lens) which is partially visible in FIG. 3 through an aperture112 in lens barrel 110. Lens barrel 110 may include a substantiallycylindrical extension 114 which may be used to interface lens barrel 110with an aperture 122 in housing 120.

Infrared sensor assembly 128 may be implemented, for example, with a cap130 (e.g., a lid) mounted on a substrate 140. Infrared sensor assembly128 may include a plurality of infrared sensors 132 (e.g., infrareddetectors) implemented in an array or other fashion on substrate 140 andcovered by cap 130. For example, in one embodiment, infrared sensorassembly 128 may be implemented as a focal plane array (FPA). Such afocal plane array may be implemented, for example, as a vacuum packageassembly (e.g., sealed by cap 130 and substrate 140). In one embodiment,infrared sensor assembly 128 may be implemented as a wafer level package(e.g., infrared sensor assembly 128 may be singulated from a set ofvacuum package assemblies provided on a wafer). In one embodiment,infrared sensor assembly 128 may be implemented to operate using a powersupply of approximately 2.4 volts, 2.5 volts, 2.8 volts, or similarvoltages.

Infrared sensors 132 may be configured to detect infrared radiation(e.g., infrared energy) from a target scene including, for example, midwave infrared wave bands (MWIR), long wave infrared wave bands (LWIR),and/or other thermal imaging bands as may be desired in particularimplementations. In one embodiment, infrared sensor assembly 128 may beprovided in accordance with wafer level packaging techniques.

Infrared sensors 132 may be implemented, for example, as microbolometersor other types of thermal imaging infrared sensors arranged in anydesired array pattern to provide a plurality of pixels. In oneembodiment, infrared sensors 132 may be implemented as vanadium oxide(VOx) detectors with a 17 μm pixel pitch. In various embodiments, arraysof approximately 32 by 32 infrared sensors 132, approximately 64 by 64infrared sensors 132, approximately 80 by 64 infrared sensors 132, orother array sizes may be used.

Substrate 140 may include various circuitry including, for example, aread out integrated circuit (ROIC) with dimensions less thanapproximately 5.5 mm by 5.5 mm in one embodiment. Substrate 140 may alsoinclude bond pads 142 that may be used to contact complementaryconnections positioned on inside surfaces of housing 120 when infraredimaging module 100 is assembled as shown in FIGS. 5A, 5B, and 5C. In oneembodiment, the ROTC may be implemented with low-dropout regulators(LDO) to perform voltage regulation to reduce power supply noiseintroduced to infrared sensor assembly 128 and thus provide an improvedpower supply rejection ratio (PSRR). Moreover, by implementing the LDOwith the ROIC (e.g., within a wafer level package), less die area may beconsumed and fewer discrete die (or chips) are needed.

FIG. 4 illustrates a block diagram of infrared sensor assembly 128including an array of infrared sensors 132 in accordance with anembodiment of the disclosure. In the illustrated embodiment, infraredsensors 132 are provided as part of a unit cell array of a ROTC 402.ROIC 402 includes bias generation and timing control circuitry 404,column amplifiers 405, a column multiplexer 406, a row multiplexer 408,and an output amplifier 410. Image frames (e.g., thermal images)captured by infrared sensors 132 may be provided by output amplifier 410to processing module 160, processor 195, and/or any other appropriatecomponents to perform various processing techniques described herein.Although an 8 by 8 array is shown in FIG. 4, any desired arrayconfiguration may be used in other embodiments. Further descriptions ofROICs and infrared sensors (e.g., microbolometer circuits) may be foundin U.S. Pat. No. 6,028,309 issued Feb. 22, 2000, which is incorporatedherein by reference in its entirety.

Infrared sensor assembly 128 may capture images (e.g., image frames) andprovide such images from its ROIC at various rates. Processing module160 may be used to perform appropriate processing of captured infraredimages and may be implemented in accordance with any appropriatearchitecture. In one embodiment, processing module 160 may beimplemented as an ASIC. In this regard, such an ASIC may be configuredto perform image processing with high performance and/or highefficiency. In another embodiment, processing module 160 may beimplemented with a general purpose central processing unit (CPU) whichmay be configured to execute appropriate software instructions toperform image processing, coordinate and perform image processing withvarious image processing blocks, coordinate interfacing betweenprocessing module 160 and host device 102, and/or other operations. Inyet another embodiment, processing module 160 may be implemented with afield programmable gate array (FPGA). Processing module 160 may beimplemented with other types of processing and/or logic circuits inother embodiments as would be understood by one skilled in the art.

In these and other embodiments, processing module 160 may also beimplemented with other components where appropriate, such as, volatilememory, non-volatile memory, and/or one or more interfaces (e.g.,infrared detector interfaces, inter-integrated circuit (I2C) interfaces,mobile industry processor interfaces (MIPI), joint test action group(JTAG) interfaces (e.g., IEEE 1149.1 standard test access port andboundary-scan architecture), and/or other interfaces).

In some embodiments, infrared imaging module 100 may further include oneor more actuators 199 which may be used to adjust the focus of infraredimage frames captured by infrared sensor assembly 128. For example,actuators 199 may be used to move optical element 180, infrared sensors132, and/or other components relative to each other to selectively focusand defocus infrared image frames in accordance with techniquesdescribed herein. Actuators 199 may be implemented in accordance withany type of motion-inducing apparatus or mechanism, and may positionedat any location within or external to infrared imaging module 100 asappropriate for different applications.

When infrared imaging module 100 is assembled, housing 120 maysubstantially enclose infrared sensor assembly 128, base 150, andprocessing module 160. Housing 120 may facilitate connection of variouscomponents of infrared imaging module 100. For example, in oneembodiment, housing 120 may provide electrical connections 126 toconnect various components as further described.

Electrical connections 126 (e.g., conductive electrical paths, traces,or other types of connections) may be electrically connected with bondpads 142 when infrared imaging module 100 is assembled. In variousembodiments, electrical connections 126 may be embedded in housing 120,provided on inside surfaces of housing 120, and/or otherwise provided byhousing 120. Electrical connections 126 may terminate in connections 124protruding from the bottom surface of housing 120 as shown in FIG. 3.Connections 124 may connect with circuit board 170 when infrared imagingmodule 100 is assembled (e.g., housing 120 may rest atop circuit board170 in various embodiments). Processing module 160 may be electricallyconnected with circuit board 170 through appropriate electricalconnections. As a result, infrared sensor assembly 128 may beelectrically connected with processing module 160 through, for example,conductive electrical paths provided by: bond pads 142, complementaryconnections on inside surfaces of housing 120, electrical connections126 of housing 120, connections 124, and circuit board 170.Advantageously, such an arrangement may be implemented without requiringwire bonds to be provided between infrared sensor assembly 128 andprocessing module 160.

In various embodiments, electrical connections 126 in housing 120 may bemade from any desired material (e.g., copper or any other appropriateconductive material). In one embodiment, electrical connections 126 mayaid in dissipating heat from infrared imaging module 100.

Other connections may be used in other embodiments. For example, in oneembodiment, sensor assembly 128 may be attached to processing module 160through a ceramic board that connects to sensor assembly 128 by wirebonds and to processing module 160 by a ball grid array (BGA). Inanother embodiment, sensor assembly 128 may be mounted directly on arigid flexible board and electrically connected with wire bonds, andprocessing module 160 may be mounted and connected to the rigid flexibleboard with wire bonds or a BGA.

The various implementations of infrared imaging module 100 and hostdevice 102 set forth herein are provided for purposes of example, ratherthan limitation. In this regard, any of the various techniques describedherein may be applied to any infrared camera system, infrared imager, orother device for performing infrared/thermal imaging.

Substrate 140 of infrared sensor assembly 128 may be mounted on base150. In various embodiments, base 150 (e.g., a pedestal) may be made,for example, of copper formed by metal injection molding (MIM) andprovided with a black oxide or nickel-coated finish. In variousembodiments, base 150 may be made of any desired material, such as forexample zinc, aluminum, or magnesium, as desired for a given applicationand may be formed by any desired applicable process, such as for examplealuminum casting, MIM, or zinc rapid casting, as may be desired forparticular applications. In various embodiments, base 150 may beimplemented to provide structural support, various circuit paths,thermal heat sink properties, and other features where appropriate. Inone embodiment, base 150 may be a multi-layer structure implemented atleast in part using ceramic material.

In various embodiments, circuit board 170 may receive housing 120 andthus may physically support the various components of infrared imagingmodule 100. In various embodiments, circuit board 170 may be implementedas a printed circuit board (e.g., an FR4 circuit board or other types ofcircuit boards), a rigid or flexible interconnect (e.g., tape or othertype of interconnects), a flexible circuit substrate, a flexible plasticsubstrate, or other appropriate structures. In various embodiments, base150 may be implemented with the various features and attributesdescribed for circuit board 170, and vice versa.

Socket 104 may include a cavity 106 configured to receive infraredimaging module 100 (e.g., as shown in the assembled view of FIG. 2).Infrared imaging module 100 and/or socket 104 may include appropriatetabs, arms, pins, fasteners, or any other appropriate engagement memberswhich may be used to secure infrared imaging module 100 to or withinsocket 104 using friction, tension, adhesion, and/or any otherappropriate manner. Socket 104 may include engagement members 107 thatmay engage surfaces 109 of housing 120 when infrared imaging module 100is inserted into a cavity 106 of socket 104. Other types of engagementmembers may be used in other embodiments.

Infrared imaging module 100 may be electrically connected with socket104 through appropriate electrical connections (e.g., contacts, pins,wires, or any other appropriate connections). For example, socket 104may include electrical connections 108 which may contact correspondingelectrical connections of infrared imaging module 100 (e.g.,interconnect pads, contacts, or other electrical connections on side orbottom surfaces of circuit board 170, bond pads 142 or other electricalconnections on base 150, or other connections). Electrical connections108 may be made from any desired material (e.g., copper or any otherappropriate conductive material). In one embodiment, electricalconnections 108 may be mechanically biased to press against electricalconnections of infrared imaging module 100 when infrared imaging module100 is inserted into cavity 106 of socket 104. In one embodiment,electrical connections 108 may at least partially secure infraredimaging module 100 in socket 104. Other types of electrical connectionsmay be used in other embodiments.

Socket 104 may be electrically connected with host device 102 throughsimilar types of electrical connections. For example, in one embodiment,host device 102 may include electrical connections (e.g., solderedconnections, snap-in connections, or other connections) that connectwith electrical connections 108 passing through apertures 190. Invarious embodiments, such electrical connections may be made to thesides and/or bottom of socket 104.

Various components of infrared imaging module 100 may be implementedwith flip chip technology which may be used to mount components directlyto circuit boards without the additional clearances typically needed forwire bond connections. Flip chip connections may be used, as an example,to reduce the overall size of infrared imaging module 100 for use incompact small form factor applications. For example, in one embodiment,processing module 160 may be mounted to circuit board 170 using flipchip connections. For example, infrared imaging module 100 may beimplemented with such flip chip configurations.

In various embodiments, infrared imaging module 100 and/or associatedcomponents may be implemented in accordance with various techniques(e.g., wafer level packaging techniques) as set forth in U.S. patentapplication Ser. No. 12/844,124 filed Jul. 27, 2010, and U.S.Provisional Patent Application No. 61/469,651 filed Mar. 30, 2011, whichare incorporated herein by reference in their entirety. Furthermore, inaccordance with one or more embodiments, infrared imaging module 100and/or associated components may be implemented, calibrated, tested,and/or used in accordance with various techniques, such as for exampleas set forth in U.S. Pat. No. 7,470,902 issued Dec. 30, 2008, U.S. Pat.No. 6,028,309 issued Feb. 22, 2000, U.S. Pat. No. 6,812,465 issued Nov.2, 2004, U.S. Pat. No. 7,034,301 issued Apr. 25, 2006, U.S. Pat. No.7,679,048 issued Mar. 16, 2010, U.S. Pat. No. 7,470,904 issued Dec. 30,2008, U.S. patent application Ser. No. 12/202,880 filed Sep. 2, 2008,and U.S. patent application Ser. No. 12/202,896 filed Sep. 2, 2008,which are incorporated herein by reference in their entirety.

In some embodiments, host device 102 may include other components 198such as a non-thermal camera (e.g., a visible light camera or other typeof non-thermal imager such as a near infrared and/or short wave infraredcamera, all of which are collectively referred to herein as avisible/NIR camera or visible/NIR light camera). The non-thermal cameramay be a small form factor imaging module or imaging device, and may, insome embodiments, be implemented in a manner similar to the variousembodiments of infrared imaging module 100 disclosed herein, with one ormore sensors and/or sensor arrays responsive to radiation in non-thermalspectrums (e.g., radiation in visible light wavelengths, ultravioletwavelengths, and/or other non-thermal wavelengths). For example, in someembodiments, the non-thermal camera may be implemented with acharge-coupled device (CCD) sensor, an electron multiplying CCD (EMCCD)sensor, a complementary metal-oxide-semiconductor (CMOS) sensor, ascientific CMOS (sCMOS) sensor, or other filters and/or sensors.

In some embodiments, the non-thermal camera may be co-located withinfrared imaging module 100 and oriented such that a field-of-view (FOV)of the non-thermal camera at least partially overlaps a FOV of infraredimaging module 100. In one example, infrared imaging module 100 and anon-thermal camera may be implemented as a dual sensor module sharing acommon substrate according to various techniques described in U.S.Provisional Patent Application No. 61/748,018 filed Dec. 31, 2012, whichis incorporated herein by reference.

For embodiments having such a non-thermal light camera, variouscomponents (e.g., processor 195, processing module 160, and/or otherprocessing component) may be configured to superimpose, fuse, blend, orotherwise combine infrared images (e.g., including thermal images)captured by infrared imaging module 100 and non-thermal images (e.g.,including visible light images) captured by a non-thermal camera,whether captured at substantially the same time or different times(e.g., time-spaced over hours, days, daytime versus nighttime, and/orotherwise).

In some embodiments, thermal and non-thermal images may be processed togenerate combined images (e.g., one or more processes performed on suchimages in some embodiments). For example, scene-based NUC processing maybe performed (as further described herein), true color processing may beperformed, and/or high contrast processing may be performed. Inaddition, active illumination may be optionally used (e.g., in visible,near infrared, short wave infrared, and/or any other non-thermalwavebands as desired) to selectively illuminate a scene for capturingnon-thermal images.

Regarding true color processing, thermal images may be blended withnon-thermal images by, for example, blending a radiometric component ofa thermal image with a corresponding component of a non-thermal imageaccording to a blending parameter, which may be adjustable by a userand/or machine in some embodiments. For example, luminance orchrominance components of the thermal and non-thermal images may becombined according to the blending parameter. In one embodiment, suchblending techniques may be referred to as true color infrared imagery.For example, in daytime imaging, a blended image may comprise anon-thermal color image, which includes a luminance component and achrominance component, with its luminance value replaced and/or blendedwith the luminance value from a thermal image. The use of the luminancedata from the thermal image causes the intensity of the true non-thermalcolor image to brighten or dim based on the temperature of the object.As such, these blending techniques provide thermal imaging for daytimeor visible light images.

Regarding high contrast processing, high spatial frequency content maybe obtained from one or more of the thermal and non-thermal images(e.g., by performing high pass filtering, difference imaging, and/orother techniques). A combined image may include a radiometric componentof a thermal image and a blended component including infrared (e.g.,thermal) characteristics of a scene blended with the high spatialfrequency content, according to a blending parameter, which may beadjustable by a user and/or machine in some embodiments. In someembodiments, high spatial frequency content from non-thermal images maybe blended with thermal images by superimposing the high spatialfrequency content onto the thermal images, where the high spatialfrequency content replaces or overwrites those portions of the thermalimages corresponding to where the high spatial frequency content exists.For example, the high spatial frequency content may include edges ofobjects depicted in images of a scene, but may not exist within theinterior of such objects. In such embodiments, blended image data maysimply include the high spatial frequency content, which maysubsequently be encoded into one or more components of combined images.

For example, a radiometric component of thermal image may be achrominance component of the thermal image, and the high spatialfrequency content may be derived from the luminance and/or chrominancecomponents of a non-thermal image. In this embodiment, a combined imagemay include the radiometric component (e.g., the chrominance componentof the thermal image) encoded into a chrominance component of thecombined image and the high spatial frequency content directly encoded(e.g., as blended image data but with no thermal image contribution)into a luminance component of the combined image. By doing so, aradiometric calibration of the radiometric component of the thermalimage may be retained. In similar embodiments, blended image data mayinclude the high spatial frequency content added to a luminancecomponent of the thermal images, and the resulting blended data encodedinto a luminance component of resulting combined images.

For example, any of the techniques disclosed in the followingapplications may be used in various embodiments: U.S. patent applicationSer. No. 12/477,828 filed Jun. 3, 2009; U.S. patent application Ser. No.12/766,739 filed Apr. 23, 2010; U.S. patent application Ser. No.13/105,765 filed May 11, 2011; U.S. patent application Ser. No.13/437,645 filed Apr. 2, 2012; U.S. Provisional Patent Application No.61/473,207 filed Apr. 8, 2011; U.S. Provisional Patent Application No.61/746,069 filed Dec. 26, 2012; U.S. Provisional Patent Application No.61/746,074 filed Dec. 26, 2012; U.S. Provisional Patent Application No.61/748,018 filed Dec. 31, 2012; U.S. Provisional Patent Application No.61/792,582 filed Mar. 15, 2013; U.S. Provisional Patent Application No.61/793,952 filed Mar. 15, 2013; and International Patent Application No.PCT/EP2011/056432 filed Apr. 21, 2011, all of such applications areincorporated herein by reference in their entirety. Any of thetechniques described herein, or described in other applications orpatents referenced herein, may be applied to any of the various thermaldevices, non-thermal devices, and uses described herein.

Referring again to FIG. 1, in various embodiments, host device 102 mayinclude shutter 105. In this regard, shutter 105 may be selectivelypositioned over socket 104 (e.g., as identified by arrows 103) whileinfrared imaging module 100 is installed therein. In this regard,shutter 105 may be used, for example, to protect infrared imaging module100 when not in use. Shutter 105 may also be used as a temperaturereference as part of a calibration process (e.g., a NUC process or othercalibration processes) for infrared imaging module 100 as would beunderstood by one skilled in the art.

In various embodiments, shutter 105 may be made from various materialssuch as, for example, polymers, glass, aluminum (e.g., painted oranodized) or other materials. In various embodiments, shutter 105 mayinclude one or more coatings to selectively filter electromagneticradiation and/or adjust various optical properties of shutter 105 (e.g.,a uniform blackbody coating or a reflective gold coating).

In another embodiment, shutter 105 may be fixed in place to protectinfrared imaging module 100 at all times. In this case, shutter 105 or aportion of shutter 105 may be made from appropriate materials (e.g.,polymers or infrared transmitting materials such as silicon, germanium,zinc selenide, or chalcogenide glasses) that do not substantially filterdesired infrared wavelengths. In another embodiment, a shutter may beimplemented as part of infrared imaging module 100 (e.g., within or aspart of a lens barrel or other components of infrared imaging module100), as would be understood by one skilled in the art.

Alternatively, in another embodiment, a shutter (e.g., shutter 105 orother type of external or internal shutter) need not be provided, butrather a NUC process or other type of calibration may be performed usingshutterless techniques. In another embodiment, a NUC process or othertype of calibration using shutterless techniques may be performed incombination with shutter-based techniques.

Infrared imaging module 100 and host device 102 may be implemented inaccordance with any of the various techniques set forth in U.S.Provisional Patent Application No. 61/495,873 filed Jun. 10, 2011, U.S.Provisional Patent Application No. 61/495,879 filed Jun. 10, 2011, andU.S. Provisional Patent Application No. 61/495,888 filed Jun. 10, 2011,which are incorporated herein by reference in their entirety.

In various embodiments, the components of host device 102 and/orinfrared imaging module 100 may be implemented as a local or distributedsystem with components in communication with each other over wiredand/or wireless networks. Accordingly, the various operations identifiedin this disclosure may be performed by local and/or remote components asmay be desired in particular implementations.

FIG. 5 illustrates a flow diagram of various operations to determine NUCterms in accordance with an embodiment of the disclosure. In someembodiments, the operations of FIG. 5 may be performed by processingmodule 160 or processor 195 (both also generally referred to as aprocessor) operating on image frames captured by infrared sensors 132.

In block 505, infrared sensors 132 begin capturing image frames of ascene. Typically, the scene will be the real world environment in whichhost device 102 is currently located. In this regard, shutter 105 (ifoptionally provided) may be opened to permit infrared imaging module toreceive infrared radiation from the scene. Infrared sensors 132 maycontinue capturing image frames during all operations shown in FIG. 5.In this regard, the continuously captured image frames may be used forvarious operations as further discussed. In one embodiment, the capturedimage frames may be temporally filtered (e.g., in accordance with theprocess of block 826 further described herein with regard to FIG. 8) andbe processed by other terms (e.g., factory gain terms 812, factoryoffset terms 816, previously determined NUC terms 817, column FPN terms820, and row FPN terms 824 as further described herein with regard toFIG. 8) before they are used in the operations shown in FIG. 5.

In block 510, a NUC process initiating event is detected. In oneembodiment, the NUC process may be initiated in response to physicalmovement of host device 102. Such movement may be detected, for example,by motion sensors 194 which may be polled by a processor. In oneexample, a user may move host device 102 in a particular manner, such asby intentionally waving host device 102 back and forth in an “erase” or“swipe” movement. In this regard, the user may move host device 102 inaccordance with a predetermined speed and direction (velocity), such asin an up and down, side to side, or other pattern to initiate the NUCprocess. In this example, the use of such movements may permit the userto intuitively operate host device 102 to simulate the “erasing” ofnoise in captured image frames.

In another example, a NUC process may be initiated by host device 102 ifmotion exceeding a threshold value is exceeded (e.g., motion greaterthan expected for ordinary use). It is contemplated that any desiredtype of spatial translation of host device 102 may be used to initiatethe NUC process.

In yet another example, a NUC process may be initiated by host device102 if a minimum time has elapsed since a previously performed NUCprocess. In a further example, a NUC process may be initiated by hostdevice 102 if infrared imaging module 100 has experienced a minimumtemperature change since a previously performed NUC process. In a stillfurther example, a NUC process may be continuously initiated andrepeated.

In block 515, after a NUC process initiating event is detected, it isdetermined whether the NUC process should actually be performed. In thisregard, the NUC process may be selectively initiated based on whetherone or more additional conditions are met. For example, in oneembodiment, the NUC process may not be performed unless a minimum timehas elapsed since a previously performed NUC process. In anotherembodiment, the NUC process may not be performed unless infrared imagingmodule 100 has experienced a minimum temperature change since apreviously performed NUC process. Other criteria or conditions may beused in other embodiments. If appropriate criteria or conditions havebeen met, then the flow diagram continues to block 520. Otherwise, theflow diagram returns to block 505.

In the NUC process, blurred image frames may be used to determine NUCterms which may be applied to captured image frames to correct for FPN.As discussed, in one embodiment, the blurred image frames may beobtained by accumulating multiple image frames of a moving scene (e.g.,captured while the scene and/or the thermal imager is in motion). Inanother embodiment, the blurred image frames may be obtained bydefocusing an optical element or other component of the thermal imager.

Accordingly, in block 520 a choice of either approach is provided. Ifthe motion-based approach is used, then the flow diagram continues toblock 525. If the defocus-based approach is used, then the flow diagramcontinues to block 530.

Referring now to the motion-based approach, in block 525 motion isdetected. For example, in one embodiment, motion may be detected basedon the image frames captured by infrared sensors 132. In this regard, anappropriate motion detection process (e.g., an image registrationprocess, a frame-to-frame difference calculation, or other appropriateprocess) may be applied to captured image frames to determine whethermotion is present (e.g., whether static or moving image frames have beencaptured). For example, in one embodiment, it can be determined whetherpixels or regions around the pixels of consecutive image frames havechanged more than a user defined amount (e.g., a percentage and/orthreshold value). If at least a given percentage of pixels have changedby at least the user defined amount, then motion will be detected withsufficient certainty to proceed to block 535.

In another embodiment, motion may be determined on a per pixel basis,wherein only pixels that exhibit significant changes are accumulated toprovide the blurred image frame. For example, counters may be providedfor each pixel and used to ensure that the same number of pixel valuesare accumulated for each pixel, or used to average the pixel valuesbased on the number of pixel values actually accumulated for each pixel.Other types of image-based motion detection may be performed such asperforming a Radon transform.

In another embodiment, motion may be detected based on data provided bymotion sensors 194. In one embodiment, such motion detection may includedetecting whether host device 102 is moving along a relatively straighttrajectory through space. For example, if host device 102 is movingalong a relatively straight trajectory, then it is possible that certainobjects appearing in the imaged scene may not be sufficiently blurred(e.g., objects in the scene that may be aligned with or movingsubstantially parallel to the straight trajectory). Thus, in such anembodiment, the motion detected by motion sensors 194 may be conditionedon host device 102 exhibiting, or not exhibiting, particulartrajectories.

In yet another embodiment, both a motion detection process and motionsensors 194 may be used. Thus, using any of these various embodiments, adetermination can be made as to whether or not each image frame wascaptured while at least a portion of the scene and host device 102 werein motion relative to each other (e.g., which may be caused by hostdevice 102 moving relative to the scene, at least a portion of the scenemoving relative to host device 102, or both).

It is expected that the image frames for which motion was detected mayexhibit some secondary blurring of the captured scene (e.g., blurredthermal image data associated with the scene) due to the thermal timeconstants of infrared sensors 132 (e.g., microbolometer thermal timeconstants) interacting with the scene movement.

In block 535, image frames for which motion was detected areaccumulated. For example, if motion is detected for a continuous seriesof image frames, then the image frames of the series may be accumulated.As another example, if motion is detected for only some image frames,then the non-moving image frames may be skipped and not included in theaccumulation. Thus, a continuous or discontinuous set of image framesmay be selected to be accumulated based on the detected motion.

In block 540, the accumulated image frames are averaged to provide ablurred image frame. Because the accumulated image frames were capturedduring motion, it is expected that actual scene information will varybetween the image frames and thus cause the scene information to befurther blurred in the resulting blurred image frame (block 545).

In contrast, FPN (e.g., caused by one or more components of infraredimaging module 100) will remain fixed over at least short periods oftime and over at least limited changes in scene irradiance duringmotion. As a result, image frames captured in close proximity in timeand space during motion will suffer from identical or at least verysimilar FPN. Thus, although scene information may change in consecutiveimage frames, the FPN will stay essentially constant. By averaging,multiple image frames captured during motion will blur the sceneinformation, but will not blur the FPN. As a result, FPN will remainmore clearly defined in the blurred image frame provided in block 545than the scene information.

In one embodiment, 32 or more image frames are accumulated and averagedin blocks 535 and 540. However, any desired number of image frames maybe used in other embodiments, but with generally decreasing correctionaccuracy as frame count is decreased.

Referring now to the defocus-based approach, in block 530, a defocusoperation may be performed to intentionally defocus the image framescaptured by infrared sensors 132. For example, in one embodiment, one ormore actuators 199 may be used to adjust, move, or otherwise translateoptical element 180, infrared sensor assembly 128, and/or othercomponents of infrared imaging module 100 to cause infrared sensors 132to capture a blurred (e.g., unfocused) image frame of the scene. Othernon-actuator based techniques are also contemplated for intentionallydefocusing infrared image frames such as, for example, manual (e.g.,user-initiated) defocusing.

Although the scene may appear blurred in the image frame, FPN (e.g.,caused by one or more components of infrared imaging module 100) willremain unaffected by the defocusing operation. As a result, a blurredimage frame of the scene will be provided (block 545) with FPN remainingmore clearly defined in the blurred image than the scene information.

In the above discussion, the defocus-based approach has been describedwith regard to a single captured image frame. In another embodiment, thedefocus-based approach may include accumulating multiple image frameswhile the infrared imaging module 100 has been defocused and averagingthe defocused image frames to remove the effects of temporal noise andprovide a blurred image frame in block 545.

Thus, it will be appreciated that a blurred image frame may be providedin block 545 by either the motion-based approach or the defocus-basedapproach. Because much of the scene information will be blurred byeither motion, defocusing, or both, the blurred image frame may beeffectively considered a low pass filtered version of the originalcaptured image frames with respect to scene information.

In block 550, the blurred image frame is processed to determine updatedrow and column FPN terms (e.g., if row and column FPN terms have notbeen previously determined then the updated row and column FPN terms maybe new row and column FPN terms in the first iteration of block 550). Asused in this disclosure, the terms row and column may be usedinterchangeably depending on the orientation of infrared sensors 132and/or other components of infrared imaging module 100.

In one embodiment, block 550 includes determining a spatial FPNcorrection term for each row of the blurred image frame (e.g., each rowmay have its own spatial FPN correction term), and also determining aspatial FPN correction term for each column of the blurred image frame(e.g., each column may have its own spatial FPN correction term). Suchprocessing may be used to reduce the spatial and slowly varying (1/f)row and column FPN inherent in thermal imagers caused by, for example,1/f noise characteristics of amplifiers in ROIC 402 which may manifestas vertical and horizontal stripes in image frames.

Advantageously, by determining spatial row and column FPN terms usingthe blurred image frame, there will be a reduced risk of vertical andhorizontal objects in the actual imaged scene from being mistaken forrow and column noise (e.g., real scene content will be blurred while FPNremains unblurred).

In one embodiment, row and column FPN terms may be determined byconsidering differences between neighboring pixels of the blurred imageframe. For example, FIG. 6 illustrates differences between neighboringpixels in accordance with an embodiment of the disclosure. Specifically,in FIG. 6 a pixel 610 is compared to its 8 nearest horizontal neighbors:d0-d3 on one side and d4-d7 on the other side. Differences between theneighbor pixels can be averaged to obtain an estimate of the offseterror of the illustrated group of pixels. An offset error may becalculated for each pixel in a row or column and the average result maybe used to correct the entire row or column.

To prevent real scene data from being interpreted as noise, upper andlower threshold values may be used (thPix and −thPix). Pixel valuesfalling outside these threshold values (pixels d1 and d4 in thisexample) are not used to obtain the offset error. In addition, themaximum amount of row and column FPN correction may be limited by thesethreshold values.

Further techniques for performing spatial row and column FPN correctionprocessing are set forth in U.S. patent application Ser. No. 12/396,340filed Mar. 2, 2009 which is incorporated herein by reference in itsentirety.

Referring again to FIG. 5, the updated row and column FPN termsdetermined in block 550 are stored (block 552) and applied (block 555)to the blurred image frame provided in block 545. After these terms areapplied, some of the spatial row and column FPN in the blurred imageframe may be reduced. However, because such terms are applied generallyto rows and columns, additional FPN may remain such as spatiallyuncorrelated FPN associated with pixel to pixel drift or other causes.Neighborhoods of spatially correlated FPN may also remain which may notbe directly associated with individual rows and columns. Accordingly,further processing may be performed as discussed below to determine NUCterms.

In block 560, local contrast values (e.g., edges or absolute values ofgradients between adjacent or small groups of pixels) in the blurredimage frame are determined. If scene information in the blurred imageframe includes contrasting areas that have not been significantlyblurred (e.g., high contrast edges in the original scene data), thensuch features may be identified by a contrast determination process inblock 560.

For example, local contrast values in the blurred image frame may becalculated, or any other desired type of edge detection process may beapplied to identify certain pixels in the blurred image as being part ofan area of local contrast. Pixels that are marked in this manner may beconsidered as containing excessive high spatial frequency sceneinformation that would be interpreted as FPN (e.g., such regions maycorrespond to portions of the scene that have not been sufficientlyblurred). As such, these pixels may be excluded from being used in thefurther determination of NUC terms. In one embodiment, such contrastdetection processing may rely on a threshold that is higher than theexpected contrast value associated with FPN (e.g., pixels exhibiting acontrast value higher than the threshold may be considered to be sceneinformation, and those lower than the threshold may be considered to beexhibiting FPN).

In one embodiment, the contrast determination of block 560 may beperformed on the blurred image frame after row and column FPN terms havebeen applied to the blurred image frame (e.g., as shown in FIG. 5). Inanother embodiment, block 560 may be performed prior to block 550 todetermine contrast before row and column FPN terms are determined (e.g.,to prevent scene based contrast from contributing to the determinationof such terms).

Following block 560, it is expected that any high spatial frequencycontent remaining in the blurred image frame may be generally attributedto spatially uncorrelated FPN. In this regard, following block 560, muchof the other noise or actual desired scene based information has beenremoved or excluded from the blurred image frame due to: intentionalblurring of the image frame (e.g., by motion or defocusing in blocks 520through 545), application of row and column FPN terms (block 555), andcontrast determination (block 560).

Thus, it can be expected that following block 560, any remaining highspatial frequency content (e.g., exhibited as areas of contrast ordifferences in the blurred image frame) may be attributed to spatiallyuncorrelated FPN. Accordingly, in block 565, the blurred image frame ishigh pass filtered. In one embodiment, this may include applying a highpass filter to extract the high spatial frequency content from theblurred image frame. In another embodiment, this may include applying alow pass filter to the blurred image frame and taking a differencebetween the low pass filtered image frame and the unfiltered blurredimage frame to obtain the high spatial frequency content. In accordancewith various embodiments of the present disclosure, a high pass filtermay be implemented by calculating a mean difference between a sensorsignal (e.g., a pixel value) and its neighbors.

In block 570, a flat field correction process is performed on the highpass filtered blurred image frame to determine updated NUC terms (e.g.,if a NUC process has not previously been performed then the updated NUCterms may be new NUC terms in the first iteration of block 570).

For example, FIG. 7 illustrates a flat field correction technique 700 inaccordance with an embodiment of the disclosure. In FIG. 7, a NUC termmay be determined for each pixel 710 of the blurred image frame usingthe values of its neighboring pixels 712 to 726. For each pixel 710,several gradients may be determined based on the absolute differencebetween the values of various adjacent pixels. For example, absolutevalue differences may be determined between: pixels 712 and 714 (a leftto right diagonal gradient), pixels 716 and 718 (a top to bottomvertical gradient), pixels 720 and 722 (a right to left diagonalgradient), and pixels 724 and 726 (a left to right horizontal gradient).

These absolute differences may be summed to provide a summed gradientfor pixel 710. A weight value may be determined for pixel 710 that isinversely proportional to the summed gradient. This process may beperformed for all pixels 710 of the blurred image frame until a weightvalue is provided for each pixel 710. For areas with low gradients(e.g., areas that are blurry or have low contrast), the weight valuewill be close to one. Conversely, for areas with high gradients, theweight value will be zero or close to zero. The update to the NUC termas estimated by the high pass filter is multiplied with the weightvalue.

In one embodiment, the risk of introducing scene information into theNUC terms can be further reduced by applying some amount of temporaldamping to the NUC term determination process. For example, a temporaldamping factor λ between 0 and 1 may be chosen such that the new NUCterm (NUC_(NEW)) stored is a weighted average of the old NUC term(NUC_(OLD)) and the estimated updated NUC term (NUC_(UPDATE)). In oneembodiment, this can be expressed asNUC_(NEW)=λ·NUC_(OLD)+(1−λ)·(NUC_(OLD)+NUC_(UPDATE)).

Although the determination of NUC terms has been described with regardto gradients, local contrast values may be used instead whereappropriate. Other techniques may also be used such as, for example,standard deviation calculations. Other types flat field correctionprocesses may be performed to determine NUC terms including, forexample, various processes identified in U.S. Pat. No. 6,028,309 issuedFeb. 22, 2000, U.S. Pat. No. 6,812,465 issued Nov. 2, 2004, and U.S.patent application Ser. No. 12/114,865 filed May 5, 2008, which areincorporated herein by reference in their entirety.

Referring again to FIG. 5, block 570 may include additional processingof the NUC terms. For example, in one embodiment, to preserve the scenesignal mean, the sum of all NUC terms may be normalized to zero bysubtracting the NUC term mean from each NUC term. Also in block 570, toavoid row and column noise from affecting the NUC terms, the mean valueof each row and column may be subtracted from the NUC terms for each rowand column. As a result, row and column FPN filters using the row andcolumn FPN terms determined in block 550 may be better able to filterout row and column noise in further iterations (e.g., as further shownin FIG. 8) after the NUC terms are applied to captured images (e.g., inblock 580 further discussed herein). In this regard, the row and columnFPN filters may in general use more data to calculate the per row andper column offset coefficients (e.g., row and column FPN terms) and maythus provide a more robust alternative for reducing spatially correlatedFPN than the NUC terms which are based on high pass filtering to capturespatially uncorrelated noise.

In blocks 571-573, additional high pass filtering and furtherdeterminations of updated NUC terms may be optionally performed toremove spatially correlated FPN with lower spatial frequency thanpreviously removed by row and column FPN terms. In this regard, somevariability in infrared sensors 132 or other components of infraredimaging module 100 may result in spatially correlated FPN noise thatcannot be easily modeled as row or column noise. Such spatiallycorrelated FPN may include, for example, window defects on a sensorpackage or a cluster of infrared sensors 132 that respond differently toirradiance than neighboring infrared sensors 132. In one embodiment,such spatially correlated FPN may be mitigated with an offsetcorrection. If the amount of such spatially correlated FPN issignificant, then the noise may also be detectable in the blurred imageframe. Since this type of noise may affect a neighborhood of pixels, ahigh pass filter with a small kernel may not detect the FPN in theneighborhood (e.g., all values used in high pass filter may be takenfrom the neighborhood of affected pixels and thus may be affected by thesame offset error). For example, if the high pass filtering of block 565is performed with a small kernel (e.g., considering only immediatelyadjacent pixels that fall within a neighborhood of pixels affected byspatially correlated FPN), then broadly distributed spatially correlatedFPN may not be detected.

For example, FIG. 11 illustrates spatially correlated FPN in aneighborhood of pixels in accordance with an embodiment of thedisclosure. As shown in a sample image frame 1100, a neighborhood ofpixels 1110 may exhibit spatially correlated FPN that is not preciselycorrelated to individual rows and columns and is distributed over aneighborhood of several pixels (e.g., a neighborhood of approximately 4by 4 pixels in this example). Sample image frame 1100 also includes aset of pixels 1120 exhibiting substantially uniform response that arenot used in filtering calculations, and a set of pixels 1130 that areused to estimate a low pass value for the neighborhood of pixels 1110.In one embodiment, pixels 1130 may be a number of pixels divisible bytwo in order to facilitate efficient hardware or software calculations.

Referring again to FIG. 5, in blocks 571-573, additional high passfiltering and further determinations of updated NUC terms may beoptionally performed to remove spatially correlated FPN such asexhibited by pixels 1110. In block 571, the updated NUC terms determinedin block 570 are applied to the blurred image frame. Thus, at this time,the blurred image frame will have been initially corrected for spatiallycorrelated FPN (e.g., by application of the updated row and column FPNterms in block 555), and also initially corrected for spatiallyuncorrelated FPN (e.g., by application of the updated NUC terms appliedin block 571).

In block 572, a further high pass filter is applied with a larger kernelthan was used in block 565, and further updated NUC terms may bedetermined in block 573. For example, to detect the spatially correlatedFPN present in pixels 1110, the high pass filter applied in block 572may include data from a sufficiently large enough neighborhood of pixelssuch that differences can be determined between unaffected pixels (e.g.,pixels 1120) and affected pixels (e.g., pixels 1110). For example, a lowpass filter with a large kernel can be used (e.g., an N by N kernel thatis much greater than 3 by 3 pixels) and the results may be subtracted toperform appropriate high pass filtering.

In one embodiment, for computational efficiency, a sparse kernel may beused such that only a small number of neighboring pixels inside an N byN neighborhood are used. For any given high pass filter operation usingdistant neighbors (e.g., a large kernel), there is a risk of modelingactual (potentially blurred) scene information as spatially correlatedFPN. Accordingly, in one embodiment, the temporal damping factor λ maybe set close to 1 for updated NUC terms determined in block 573.

In various embodiments, blocks 571-573 may be repeated (e.g., cascaded)to iteratively perform high pass filtering with increasing kernel sizesto provide further updated NUC terms further correct for spatiallycorrelated FPN of desired neighborhood sizes. In one embodiment, thedecision to perform such iterations may be determined by whetherspatially correlated FPN has actually been removed by the updated NUCterms of the previous performance of blocks 571-573.

After blocks 571-573 are finished, a decision is made regarding whetherto apply the updated NUC terms to captured image frames (block 574). Forexample, if an average of the absolute value of the NUC terms for theentire image frame is less than a minimum threshold value, or greaterthan a maximum threshold value, the NUC terms may be deemed spurious orunlikely to provide meaningful correction. Alternatively, thresholdingcriteria may be applied to individual pixels to determine which pixelsreceive updated NUC terms. In one embodiment, the threshold values maycorrespond to differences between the newly calculated NUC terms andpreviously calculated NUC terms. In another embodiment, the thresholdvalues may be independent of previously calculated NUC terms. Othertests may be applied (e.g., spatial correlation tests) to determinewhether the NUC terms should be applied.

If the NUC terms are deemed spurious or unlikely to provide meaningfulcorrection, then the flow diagram returns to block 505. Otherwise, thenewly determined NUC terms are stored (block 575) to replace previousNUC terms (e.g., determined by a previously performed iteration of FIG.5) and applied (block 580) to captured image frames.

FIG. 8 illustrates various image processing techniques of FIG. 5 andother operations applied in an image processing pipeline 800 inaccordance with an embodiment of the disclosure. In this regard,pipeline 800 identifies various operations of FIG. 5 in the context ofan overall iterative image processing scheme for correcting image framesprovided by infrared imaging module 100. In some embodiments, pipeline800 may be provided by processing module 160 or processor 195 (both alsogenerally referred to as a processor) operating on image frames capturedby infrared sensors 132.

Image frames captured by infrared sensors 132 may be provided to a frameaverager 804 that integrates multiple image frames to provide imageframes 802 with an improved signal to noise ratio. Frame averager 804may be effectively provided by infrared sensors 132, ROIC 402, and othercomponents of infrared sensor assembly 128 that are implemented tosupport high image capture rates. For example, in one embodiment,infrared sensor assembly 128 may capture infrared image frames at aframe rate of 240 Hz (e.g., 240 images per second). In this embodiment,such a high frame rate may be implemented, for example, by operatinginfrared sensor assembly 128 at relatively low voltages (e.g.,compatible with mobile telephone voltages) and by using a relativelysmall array of infrared sensors 132 (e.g., an array of 64 by 64 infraredsensors in one embodiment).

In one embodiment, such infrared image frames may be provided frominfrared sensor assembly 128 to processing module 160 at a high framerate (e.g., 240 Hz or other frame rates). In another embodiment,infrared sensor assembly 128 may integrate over longer time periods, ormultiple time periods, to provide integrated (e.g., averaged) infraredimage frames to processing module 160 at a lower frame rate (e.g., 30Hz, 9 Hz, or other frame rates). Further information regardingimplementations that may be used to provide high image capture rates maybe found in U.S. Provisional Patent Application No. 61/495,879 filedJun. 10, 2011 which is incorporated herein by reference in its entirety.

Image frames 802 proceed through pipeline 800 where they are adjusted byvarious terms, temporally filtered, used to determine the variousadjustment terms, and gain compensated.

In blocks 810 and 814, factory gain terms 812 and factory offset terms816 are applied to image frames 802 to compensate for gain and offsetdifferences, respectively, between the various infrared sensors 132and/or other components of infrared imaging module 100 determined duringmanufacturing and testing.

In block 580, NUC terms 817 are applied to image frames 802 to correctfor FPN as discussed. In one embodiment, if NUC terms 817 have not yetbeen determined (e.g., before a NUC process has been initiated), thenblock 580 may not be performed or initialization values may be used forNUC terms 817 that result in no alteration to the image data (e.g.,offsets for every pixel would be equal to zero).

In blocks 818 and 822, column FPN terms 820 and row FPN terms 824,respectively, are applied to image frames 802. Column FPN terms 820 androw FPN terms 824 may be determined in accordance with block 550 asdiscussed. In one embodiment, if the column FPN terms 820 and row FPNterms 824 have not yet been determined (e.g., before a NUC process hasbeen initiated), then blocks 818 and 822 may not be performed orinitialization values may be used for the column FPN terms 820 and rowFPN terms 824 that result in no alteration to the image data (e.g.,offsets for every pixel would be equal to zero).

In block 826, temporal filtering is performed on image frames 802 inaccordance with a temporal noise reduction (TNR) process. FIG. 9illustrates a TNR process in accordance with an embodiment of thedisclosure. In FIG. 9, a presently received image frame 802 a and apreviously temporally filtered image frame 802 b are processed todetermine a new temporally filtered image frame 802 e. Image frames 802a and 802 b include local neighborhoods of pixels 803 a and 803 bcentered around pixels 805 a and 805 b, respectively. Neighborhoods 803a and 803 b correspond to the same locations within image frames 802 aand 802 b and are subsets of the total pixels in image frames 802 a and802 b. In the illustrated embodiment, neighborhoods 803 a and 803 binclude areas of 5 by 5 pixels. Other neighborhood sizes may be used inother embodiments.

Differences between corresponding pixels of neighborhoods 803 a and 803b are determined and averaged to provide an averaged delta value 805 cfor the location corresponding to pixels 805 a and 805 b. Averaged deltavalue 805 c may be used to determine weight values in block 807 to beapplied to pixels 805 a and 805 b of image frames 802 a and 802 b.

In one embodiment, as shown in graph 809, the weight values determinedin block 807 may be inversely proportional to averaged delta value 805 csuch that weight values drop rapidly towards zero when there are largedifferences between neighborhoods 803 a and 803 b. In this regard, largedifferences between neighborhoods 803 a and 803 b may indicate thatchanges have occurred within the scene (e.g., due to motion) and pixels802 a and 802 b may be appropriately weighted, in one embodiment, toavoid introducing blur across frame-to-frame scene changes. Otherassociations between weight values and averaged delta value 805 c may beused in various embodiments.

The weight values determined in block 807 may be applied to pixels 805 aand 805 b to determine a value for corresponding pixel 805 e of imageframe 802 e (block 811). In this regard, pixel 805 e may have a valuethat is a weighted average (or other combination) of pixels 805 a and805 b, depending on averaged delta value 805 c and the weight valuesdetermined in block 807.

For example, pixel 805 e of temporally filtered image frame 802 e may bea weighted sum of pixels 805 a and 805 b of image frames 802 a and 802b. If the average difference between pixels 805 a and 805 b is due tonoise, then it may be expected that the average change betweenneighborhoods 805 a and 805 b will be close to zero (e.g., correspondingto the average of uncorrelated changes). Under such circumstances, itmay be expected that the sum of the differences between neighborhoods805 a and 805 b will be close to zero. In this case, pixel 805 a ofimage frame 802 a may both be appropriately weighted so as to contributeto the value of pixel 805 e.

However, if the sum of such differences is not zero (e.g., evendiffering from zero by a small amount in one embodiment), then thechanges may be interpreted as being attributed to motion instead ofnoise. Thus, motion may be detected based on the average changeexhibited by neighborhoods 805 a and 805 b. Under these circumstances,pixel 805 a of image frame 802 a may be weighted heavily, while pixel805 b of image frame 802 b may be weighted lightly.

Other embodiments are also contemplated. For example, although averageddelta value 805 c has been described as being determined based onneighborhoods 805 a and 805 b, in other embodiments averaged delta value805 c may be determined based on any desired criteria (e.g., based onindividual pixels or other types of groups of sets of pixels).

In the above embodiments, image frame 802 a has been described as apresently received image frame and image frame 802 b has been describedas a previously temporally filtered image frame. In another embodiment,image frames 802 a and 802 b may be first and second image framescaptured by infrared imaging module 100 that have not been temporallyfiltered.

FIG. 10 illustrates further implementation details in relation to theTNR process of block 826. As shown in FIG. 10, image frames 802 a and802 b may be read into line buffers 1010 a and 1010 b, respectively, andimage frame 802 b (e.g., the previous image frame) may be stored in aframe buffer 1020 before being read into line buffer 1010 b. In oneembodiment, line buffers 1010 a-b and frame buffer 1020 may beimplemented by a block of random access memory (RAM) provided by anyappropriate component of infrared imaging module 100 and/or host device102.

Referring again to FIG. 8, image frame 802 e may be passed to anautomatic gain compensation block 828 for further processing to providea result image frame 830 that may be used by host device 102 as desired.

FIG. 8 further illustrates various operations that may be performed todetermine row and column FPN terms and NUC terms as discussed. In oneembodiment, these operations may use image frames 802 e as shown in FIG.8. Because image frames 802 e have already been temporally filtered, atleast some temporal noise may be removed and thus will not inadvertentlyaffect the determination of row and column FPN terms 824 and 820 and NUCterms 817. In another embodiment, non-temporally filtered image frames802 may be used.

In FIG. 8, blocks 510, 515, and 520 of FIG. 5 are collectivelyrepresented together. As discussed, a NUC process may be selectivelyinitiated and performed in response to various NUC process initiatingevents and based on various criteria or conditions. As also discussed,the NUC process may be performed in accordance with a motion-basedapproach (blocks 525, 535, and 540) or a defocus-based approach (block530) to provide a blurred image frame (block 545). FIG. 8 furtherillustrates various additional blocks 550, 552, 555, 560, 565, 570, 571,572, 573, and 575 previously discussed with regard to FIG. 5.

As shown in FIG. 8, row and column FPN terms 824 and 820 and NUC terms817 may be determined and applied in an iterative fashion such thatupdated terms are determined using image frames 802 to which previousterms have already been applied. As a result, the overall process ofFIG. 8 may repeatedly update and apply such terms to continuously reducethe noise in image frames 830 to be used by host device 102.

Referring again to FIG. 10, further implementation details areillustrated for various blocks of FIGS. 5 and 8 in relation to pipeline800. For example, blocks 525, 535, and 540 are shown as operating at thenormal frame rate of image frames 802 received by pipeline 800. In theembodiment shown in FIG. 10, the determination made in block 525 isrepresented as a decision diamond used to determine whether a givenimage frame 802 has sufficiently changed such that it may be consideredan image frame that will enhance the blur if added to other image framesand is therefore accumulated (block 535 is represented by an arrow inthis embodiment) and averaged (block 540).

Also in FIG. 10, the determination of column FPN terms 820 (block 550)is shown as operating at an update rate that in this example is 1/32 ofthe sensor frame rate (e.g., normal frame rate) due to the averagingperformed in block 540. Other update rates may be used in otherembodiments. Although only column FPN terms 820 are identified in FIG.10, row FPN terms 824 may be implemented in a similar fashion at thereduced frame rate.

FIG. 10 also illustrates further implementation details in relation tothe NUC determination process of block 570. In this regard, the blurredimage frame may be read to a line buffer 1030 (e.g., implemented by ablock of RAM provided by any appropriate component of infrared imagingmodule 100 and/or host device 102). The flat field correction technique700 of FIG. 7 may be performed on the blurred image frame.

In view of the present disclosure, it will be appreciated thattechniques described herein may be used to remove various types of FPN(e.g., including very high amplitude FPN) such as spatially correlatedrow and column FPN and spatially uncorrelated FPN.

Other embodiments are also contemplated. For example, in one embodiment,the rate at which row and column FPN terms and/or NUC terms are updatedcan be inversely proportional to the estimated amount of blur in theblurred image frame and/or inversely proportional to the magnitude oflocal contrast values (e.g., determined in block 560).

In various embodiments, the described techniques may provide advantagesover conventional shutter-based noise correction techniques. Forexample, by using a shutterless process, a shutter (e.g., such asshutter 105) need not be provided, thus permitting reductions in size,weight, cost, and mechanical complexity. Power and maximum voltagesupplied to, or generated by, infrared imaging module 100 may also bereduced if a shutter does not need to be mechanically operated.Reliability will be improved by removing the shutter as a potentialpoint of failure. A shutterless process also eliminates potential imageinterruption caused by the temporary blockage of the imaged scene by ashutter.

Also, by correcting for noise using intentionally blurred image framescaptured from a real world scene (not a uniform scene provided by ashutter), noise correction may be performed on image frames that haveirradiance levels similar to those of the actual scene desired to beimaged. This can improve the accuracy and effectiveness of noisecorrection terms determined in accordance with the various describedtechniques.

Turning now to FIGS. 12-16, smart surveillance camera systems andmethods using a thermal imager will now be described. According tovarious embodiments of the disclosure, a smart surveillance camerasystem may provide smart illumination and recording of a surveillancescene, by processing and analyzing thermal images of the surveillancescene captured by a thermal imager (e.g., infrared imaging module 100 ofFIG. 1). In one embodiment, a smart surveillance camera system mayinclude infrared (IR) illuminators, visible light illuminators, avisible light camera sensitive to visible and reflected near IR (NIR)light (e.g., from objects illuminated by IR illuminators), a thermalimager, and a processor. In one embodiment, the thermal imager and/orthe processor may be configured to detect objects of interest (e.g.,people, vehicles) in a scene, and control the IR illuminators, thevisible light illuminators, and/or the visible/NIR light camera based onthe detection.

For example, when an object of interest enters the field of view (FOV),the smart surveillance camera may activate the IR illuminators and/orthe visible light illuminators. Such activation may depend on the typeand/or other attributes of the object. Thus, these illuminators, whichcan become hot over time, can be turned on intermittently only whendesired or needed.

Such smart illumination may beneficially prevent accumulation of spiderwebs that adversely affect performance of conventional surveillancecameras, as well as provide other benefits described herein. Variousconventional camera systems may require active illuminators to be turnedon in low light situations (e.g., during nighttime or in a dimly litroom) constantly and continuously, which attracts insects and causesbuildup of spider webs close to cameras, and in turn may trigger thecameras to constantly record meaningless images. In contrast, the smartsurveillance camera system may reduce attraction of insects and spiderwebs in the first place by turning on illuminators intermittently onlywhen needed, and even if spurious objects such as spider webs or insectsare present, cameras do not constantly record meaningless images sincespurious objects can be detected as such by capturing and analyzingthermal images of the surveillance scene. As such, the smartsurveillance camera system may beneficially reduce power consumption byilluminators and cameras, as well as save time and effort wasted inreviewing long clips of meaningless video images.

In various embodiments, the smart surveillance camera system mayselectively capture (e.g., to transmit to a local or remote monitoringstation) images of the surveillance scene using a visible/NIR lightcamera, based on the detected presence and/or other attributes of theobjects. The smart surveillance camera system may selectively recordsuch images, for example on a local or remote storage device, based onthe detection. As described above, various light sources (e.g., visiblelight illuminators, IR illuminators) may also be selectively operated inresponse to the detection, illuminating the surveillance scene for thevisible/NIR camera, or independent from operations of the visible/NIRcamera. As may be appreciated, many useful combinations of smartillumination and recording operations may be provided by the smartsurveillance camera system.

In this regard, the smart surveillance camera system may allow users tofurther define, customize, or otherwise configure smart illumination andrecording operations. Users may configure the camera system to performspecific illumination and recording operations according to the types ofthe detected objects.

For example, in some embodiments, if a person is detected, visible lightilluminators are utilized as a spot light that tracks the person whilewithin the FOV, by selectively turning on and off visible lightilluminators each oriented for projecting light in a certain direction,or by mechanically adjusting the direction of light output from thevisible light illuminators. In another example, if a vehicle or otherlarge object is detected, as many visible light illuminators as desiredare turned on to adequately illuminate the object (e.g., create afloodlight). In another example, if an animal or other non-spuriousobject is detected, IR illuminators are turned on while the object iswithin the FOV. In another example, if a spurious object (e.g., spiderwebs, insects, tumble weed, or other objects not of interest forsurveillance purposes) is detected, no illuminator is turned on.

In these examples and others, users may configure the camera system toselectively provide images (e.g., visible/NIR light image frames and/orthermal image frames such as video feeds or still images from thevisible/NIR light camera and/or thermal imager) for a local recordingand/or a remote recording/viewing of the surveillance scene, with orwithout the activation of the various illuminators. In some embodiments,the camera system may provide users with an option for recording highcontrast, high resolution user-viewable thermal images, which mayprovide useful details even when the images are captured in low lightsituations (e.g., nighttime surveillance). Such blended thermal imagesmay be generated, in some embodiments, by blending thermal imagescaptured by the thermal imager with NIR images captured by the visiblelight camera. In such embodiments, users may, for example, set thecamera system to turn on the IR illuminators and record blended thermalimages that may be useful for determining possible causes (e.g., aperson hiding behind a bush) of detected spurious object motions, ratherthan configuring the camera system to ignore the detected spuriousobject motions (e.g., by leaving the illuminators and visible lightcamera off).

In various embodiments, the camera system may further include acommunication module for interfacing and communicating with otherexternal devices. The communication module may be configured to supportvarious communication standards and protocols for home networking (e.g.,the X10 standard), for surveillance camera networking (e.g., the OpenNetwork Video Interface Forum (ONVIF) standard), for wireless networking(e.g., the IEEE 801.11 WiFI standards, the Bluetooth™ standard, theZigBee™ standard), for general wired networking (e.g., Ethernet,HomePlug™ specification), and/or for other types of networking. Thus,for example, the camera system may also open gates and garage doors if acar is detected, turn on security lights if an object of interest isdetected, record from other surveillance cameras, and/or otherwisecontrol other networked devices based on detection of objects in thesurveillance scene.

FIG. 12 shows a block diagram of a smart surveillance camera system 1200in accordance with an embodiment of the disclosure. Camera system 1200may include a thermal imager 1202, a visible/NIR light camera 1204, oneor more IR illuminators 1206, one or more visible light illuminators1208A-1208B, a processor 1210, a communication module 1212, a storagedevice 1214, and/or miscellaneous components 1216. Camera system 1200may be attached, mounted, or otherwise installed at a desired locationto provide surveillance of a scene (e.g., scene 1230), by recording,transmitting for remote viewing/recording, or otherwise providing imagesof the scene in day or nighttime. In various embodiments, components ofcamera system 1200 may be implemented in the same or similar manner ascorresponding components of host device 102 of FIG. 1. Moreover,components of camera system 1200 may be configured to perform variousNUC processes and other processes described herein.

In some embodiments, various components of camera system 1200 may bedistributed and in communication with one another over a network 1260.In such embodiments, components may also be replicated if desired forparticular applications of camera system 1200. That is, componentsconfigured for same or similar operations may be distributed over anetwork. Further, all or part of any one of the various components maybe implemented using appropriate components of a remote device 1262(e.g., a conventional remote digital video recorder (DVR), remotemonitoring station, and/or other device) if desired. Thus, for example,all or part of processor 1210 and/or all of part of storage device 1214may be implemented or replicated at remote device 1262, and configuredto record or control recording of surveillance images as furtherdescribed herein. In another example, camera system 1200 may compriseanother visible/NIR camera 1220 located separately and remotely from ahousing 1250 in which thermal imager 1202, visible/NIR camera 1204,and/or processor 1210 may be enclosed. It will be appreciated that manyother combinations of distributed implementations of camera system 1200are possible, without departing from the scope and spirit of thedisclosure.

Thermal imager 1202 may be implemented with infrared imaging module 100of FIG. 1 or other appropriate infrared imaging devices suitable forcapturing thermal images. Thermal imager 1202 may include an FPAimplemented, for example, in accordance with various embodimentsdisclosed herein or others where appropriate. Thermal imager 1202 may beconfigured to capture, process, and/or otherwise manage thermal imagesof scene 1230. The thermal images captured, processed, and/or otherwisemanaged by thermal imager 1202 may be radiometrically normalized images.That is, pixels that make up the captured image may contain calibratedthermal data (e.g., temperature). As discussed above in connection withinfrared imaging module 100 of FIG. 1, thermal imager 1202 and/orassociated components may be calibrated using appropriate techniques sothat images captured by thermal imager 1202 are properly calibratedthermal images. In some embodiments, appropriate calibration processesmay be performed periodically by thermal imager 1202 and/or processor1210 so that thermal imager 1202, and hence the thermal images capturedby it, may maintain proper calibration.

Radiometric normalization permits thermal imager 1202 and/or processor1210 to efficiently detect, from thermal images, objects having aspecific range of temperature. Thermal imager 1202 and/or processor 1210may detect such objects efficiently and effectively, because thermalimages of objects having a specific temperature may be easilydiscernable from a background and other objects, and yet lesssusceptible to lighting conditions or obscuring. In contrast, objectdetection operations performed on visible light images or non-normalizedinfrared images (e.g., reflected NIR images captured by CMOS or CCDsensors), such as performing edge detection and/or pattern recognitionalgorithms on such images, may be computationally complex yetineffective.

For example, in one embodiment, thermal imager 1202 and/or processor1210 may be configured to detect from thermal images contiguous regionsof pixels (also referred to as “blobs” or “warm blobs”) having atemperature approximately in the range of a clothed person, for example,between approximately 75° F. (e.g., clothed part of a body) andapproximately 110° F. (e.g., exposed part of a body such as a face andhands). Such “warm blobs” may indicate presence of persons (e.g., person1232) in scene 1230, and may be analyzed further as described herein toascertain the presence of one or more persons. Thermal imager 1202and/or processor 1210 may similarly detect and discern animals, vehicles(e.g., vehicle 1234), or other objects of interest in scene 1230 bydetecting and analyzing objects having temperatures typical for objectsof interest. Thus, detection of persons, motor vehicles, animals, orother objects of interest in scene 1230 by camera system 1200 may beefficient, yet less susceptible to false detection of spurious objectssuch as a spider web fluttering in the wind.

In addition, for various embodiments the captured thermal images may bescale and/or perspective calibrated thermal images. That is, geometricproperties (e.g., size and position) of objects in the actual scene canbe derived from the pixel coordinates of objects in the thermal images.Scale/perspective calibration may be performed manually or automaticallyusing known techniques when camera system 1200 is first installed at adesired location. In some embodiments, automatic recalibration may alsobe performed using known techniques periodically after installation.Thus, for example, processor 1210 may be configured to determine whichilluminators and/or visible/NIR cameras to activate based on theapproximate location of objects derived from the thermal images.

In various embodiments, thermal imager 1202 may include one or moreoptical elements 1203 (e.g., infrared-transmissive lenses,infrared-transmissive prisms, infrared-reflective mirrors, infraredfiber optics, and/or other elements) for suitably collecting and routinginfrared light from scene 1230 to an FFA of thermal imager 1202. Opticalelements 1203 may also define an FOV 1205 of thermal imager 1202. In oneexample, FOV 1205 may be wide such that scene 1230 covers a larger areathan what may be covered by an FOV 1207 of visible/NIR camera 1204 or anillumination area of illuminators 1206, 1208A-1208B respectively. It iscontemplated that any desired wide and/or narrow FOVs 1205 and 1207 maybe used, and that FOVs 1205 and 1207 may overlap to any desired extent.For example, FOVs 1205 and 1207 may each be wider or narrower than eachother or substantially the same size, and may partially, substantially,or completely overlap with each other.

In these and other examples, thermal images of scene 1230 may beanalyzed to activate and/or control one or more other visible/NIRcameras having FOVs that cover areas in scene 1230 not covered by FOV1207 of visible/NIR camera 1204. For example, camera system 1200 maydetect that vehicle 1234 in scene 1230 is moving out FOV 1207 ofvisible/NIR camera 1204 and entering an FOV 1221 of remote visible/NIRcamera 1220. In such a case, camera system 1200 may turn off and/or stoprecording from visible/NIR camera 1204 and turn on and/or startrecording from remote visible/NIR camera 1220. In various embodiments,camera system 1200 may include any number of local (e.g., co-locatedwith thermal imager) and remote cameras as desired for particularapplications, and may be configured to perform, using any number of suchlocal and remote cameras, intelligent control of capturing and/orrecording operations described above and elsewhere in the disclosure.

In other embodiments, optical elements 1203 may optionally provide aswitchable FOV (e.g., a zoom lens), which may be selectable by thermalimager 1202 and/or processor 1210. Also, thermal imager 1202,visible/NIR light camera 1204, and/or camera system housing 1250 mayoptionally include appropriate drive mechanisms 1218 (e.g., actuators,motors, and/or other appropriate mechanisms or devices) that providepanning and tilting capabilities to camera system 1200. That is, in someembodiments, camera system 1200 may optionally provide pan-tilt-zoomcapabilities, generally known in the art as PTZ capabilities.

Visible/NIR light camera 1204 may be implemented with a conventionalimage sensor suitable for capturing visible and NIR light images. Forexample, conventional charge-coupled device (CCD) sensors andcomplementary metal-oxide semiconductor (CMOS) sensors are typicallysensitive to light in the NIR spectrum (e.g., 0.7-1.0 μm wavelengths) aswell as the visible light spectrum. As such, these conventional imagesensors may be capable of capturing images of reflected NIR light in lowvisible light situations if active IR illumination is available.

Visible/NIR light camera 1204 (and visible/NIR light camera 1220 furtherdiscussed herein) may be configured to capture visible images, NIRimages, short wave infrared images, and/or images in other non-thermalwavebands of at least a portion of scene 1230. Thus, althoughvisible/NIR light cameras 1204 and 1220 are generally discussed inrelation to visible and NIR images, any of the various operationsdescribed herein relating to visible/NIR light cameras 1204 and 1220 maybe performed using non-thermal images in any desired waveband.Visible/NIR light camera 1204 may be turned on or otherwise activated tocapture visible and/or NIR light images based on detection of objects inscene 1230, and in some embodiments, based further on user-definedparameters. For example, visible/NIR light camera 1204 may be turned onor otherwise activated when an object of interest (e.g., person 1232,vehicle 1234) is present within or expected to enter FOV 1207 of visiblevisible/NIR light camera 1204, based on analysis of thermal images ofscene 1230 captured by thermal imager 1202 as further described herein.In this regard, visible/NIR light camera 1204 may be co-located withthermal imager 1202 and oriented for placing at least a portion of FOV1207 within scene 1230 covered by thermal imager 1202.

Further, camera system 1200 may include any number of visible/NIR lightcameras 1204 as desired, for example, to cover a wide surveillance area.As discussed, in some embodiments, one or more visible/NIR light cameras1220 may be located separately and remotely from thermal imager 1202, inaddition to or in place of visible/NIR light camera 1204. Visible/NIRlight camera 1220 may be enclosed in its own housing, and may includeits own IR illuminators 1224 and visible light illuminators 1226. Inother aspects, visible/NIR light camera 1220 may be implemented in asimilar manner as visible/NIR light camera 1204.

In some embodiments, visible/NIR light camera 1204/1220 may use activeillumination of visible light (e.g., provided by visible lightilluminators 1208A-1208B/1226) and/or IR light (e.g., provided by IRilluminators 1206/1224) to capture useable images in low lightsituations such as nighttime surveillance. In various embodiments,camera system 1200 may determine (e.g., at processor 1210) whetheractive illumination may be needed due to inadequate ambient light. Forexample, a need for active illumination may be determined based on anindication from visible/NIR light camera 1204/1220, which may beconfigured to sense, using conventional techniques in digital imaging,whether an adequate amount of light is available for capturing useableimages. In another example, an indication of inadequate ambient lightmay be generated by a separate photocell that detects the amount ofambient light. In yet another example, other parameters, such as thetime of day, may be considered in determining a need for activeillumination.

In various embodiments, visible/NIR light camera 1204/1220 may besensitive to a spectrum that includes at least a first portion (e.g.,NIR light) and a second portion (e.g., visible light), each of which maybe actively illuminated in a selective manner. For example, activeillumination may be provided over a NIR light portion of the spectrum(e.g., NIR light provided by IR illuminators 1206/1224), while no activeillumination is provided over a visible light portion of the spectrum.In another example, active illumination may be provided over a visiblelight portion of the spectrum (e.g., visible light provided by visiblelight illuminators 1208A-1208B/1226), while no active illumination isprovided over a NIR light portion of the spectrum. In another example,active illumination may be provided over both a NIR light portion and avisible light portion of the spectrum. In yet another example, no activeillumination may be provided.

As discussed, visible/NIR light camera 1204/1220 may be sensitive toboth NIR light and visible light. Accordingly, visible/NIR light camera1204/1220 may capture images in response to both NIR light and visiblelight. As such, the spectrum of light represented in or otherwiseassociated with images captured by visible/NIR light camera 1204/1220may correspond to NIR light and/or visible light, each of which may beactively illuminated in a selective manner to improve and/or enhance adesired portion of the spectrum represented in or otherwise associatedwith the captured images.

In some embodiments, visible/NIR light camera 1204/1220 may include anIR filter, which may be selectively moved into an appropriate place inthe light path (e.g., in front of the image sensor) to block IR lightfor improved color and contrast in daytime image capture. For example,the IR filter may be attached to actuators adapted to clear the IRfilter from the light path in response to control signals fromvisible/NIR light camera 1204/1220 and/or processor 1210, which maygenerate control signals to clear the IR filter when IR illuminators1206/1224 are activated for active IR illumination in low lightsituations.

IR illuminators 1206/1224 may be implemented with appropriate lightsources or light emitters that produce IR light, including IR light inthe NIR spectrum. In one embodiment, IR illuminators 1206/1224 may beimplemented using vertical-cavity surface-emitting lasers (VCSELs),which may offer higher efficiency, higher reliability, and a morefocused emission spectrum compared with other technologies for IR lightgeneration. As it may be appreciated, implementing IR illuminators usingVCSELs may reduce power requirements of camera system 1200, which inturn may permit all or portions of camera system 1200 to be powered bybattery and/or solar panels. In other embodiments, IR illuminators1206/1224 may be implemented with light-emitting diodes (LEDs), halogenIR lamps, or other conventional IR light sources.

In various embodiments, IR illuminators 1206/1224 may be turned on orotherwise activated to illuminate at least a portion of a surveillancescene (e.g., scene 1230) with IR light, in response to control signalsfrom thermal imager 1202 and/or processor 1210. Thermal imager 1202and/or processor 1210 may activate IR illuminators 1206/1224 in responseto the detection of an object of interest in scene 1230, and in someembodiments, based on user-defined parameters as discussed herein. Forexample, IR illuminators 1206/1224 may be activated in connection withactivation of visible/NIR light camera 1204/1220, when it is determinedthat there is an inadequate amount of ambient light. In this regard,camera system 1200 may include any number of IR illuminators 1206/1224as desired or needed to provide adequate IR illumination of scene 1230.It will be appreciated that by activating IR illuminators 1206/1224instead of visible light illuminators 1208A-1208B/1226, surveillanceimages may be captured and/or recorded surreptitiously without alertingsurveillance targets (e.g., people or animals), since people and mostanimals typically cannot detect IR light.

Visible light illuminators 1208A-1208B/1226 may be implemented with anysuitable visible light source or light emitting device. In oneembodiment, LED lights may be utilized to implement visible lightilluminators 1208A-1208B/1226. In other embodiments, other lightsources, such as incandescent lamps, electroluminescent lamps,fluorescent lamps, and electrodeless lamps, may be utilized to implementvisible light illuminators 1208A-1208B/1226.

In some embodiments, each of a plurality of the visible lightilluminators may be oriented to project visible light in a certaindirection, such that when visible light illuminators are turned on andoff in a certain sequence, the resulting light beams creates a movingspotlight. For example, visible light illuminator 1208B may beextinguished or dimmed gradually while visible light illuminator 1208Amay reciprocally be turned on or brightened gradually as person 1232moves across scene 1230, thereby creating a spotlight that tracks themovement of person 1232. In this regard, camera system 1200 may includeas many visible light illuminators as desired to create a spotlight thattracks smoothly across scene 1230 in any direction. All or a largeportion of such visible light illuminators may be turned on to create afloodlight, instead of a spotlight when, for example, there is a need toilluminate a large area. In another example, any number of such visiblelight illuminators may be turned on or off to increase or decreaseillumination area as desired for creating a spotlight, a floodlight, orany size illumination area in between, based on the size or the type ofthe object in the scene.

In other embodiments, visible light illuminators 1208A-1208B/1226 mayinclude drive mechanisms 1218 (e.g., actuators, motors) configured topan, tilt, or otherwise change the direction of visible lightilluminators 1208A-1208B/1226. In such embodiments, drive mechanisms1218 may be utilized to create a moving spotlight. In variousembodiments, camera system 1200 may include as many such visible lightilluminators as desired for increasing total light output and/orillumination area. All or a large portion of such visible lightilluminators may be turned on to create a floodlight, instead of aspotlight when, for example, there is a need to illuminate a large area.In another example, any number of such visible light illuminators may beturned on as desired to create an illumination area based on the size orthe type of the object in the scene. In some embodiments, visible lightilluminators 1208A-1208B/1226 may provide an adjustable beam angle(i.e., diameter or width of a light beam), for example, using adjustablereflectors, to increase or decrease illumination area as desired forcreating a spotlight, a floodlight, or any size illumination area inbetween.

Visible light illuminators 1208A-1208B/1226 may be activated in afloodlight mode, a tracking spotlight mode, or other desired lightingmodes, in response to control signals from thermal imager 1202 and/orprocessor 1210. Thermal imager 1202 and/or processor 1210 may activateand/or control the operation of visible light illuminators1208A-1208B/1226 according to detection of an object of interest inscene 1230, and in some embodiments, further according to user-definedparameters as discussed herein. For example, visible light illuminators1208A-1208B/1226 may be activated to provide active illumination forcapturing surveillance images with visible/NIR light camera 1204, tolight an area for safety of drivers, pedestrians, or other persons,and/or to deter unscrupulous trespassers with a floodlight that turns onor a spotlight that tracks them.

Processor 1210 may be implemented as any appropriate processing deviceas described with regard to processor 195 in FIG. 1. In someembodiments, at least some part or some operations of processor 1210described herein may be implemented as part of thermal imager 1202, forexample, at processing module 160 described above in connection withFIG. 1. Processor 1210 may be adapted to interface and communicate withother components of camera system 1200 to perform operations andprocesses described herein.

Processor 1210 may be configured to receive thermal images of asurveillance scene (e.g., scene 1230) captured by thermal imager 1202.Processor 1210 may be configured to detect an object of interest (e.g.,person 1232, vehicle 1234) in the surveillance scene and determine thetypes (e.g., a person, a vehicle, an animal, and/or other non-spuriousobjects) of the detected objects, by processing and analyzing thereceived thermal images and the radiometric data contained therein, asfurther described in the disclosure. In some embodiments, processor 1210may be further configured to determine other attributes associated withthe detected objects, such as a position, a motion vector (i.e., speedand direction of movement), and a size.

In various embodiments, processor 1210 may be configured to generatecontrol signals to activate/deactivate or otherwise control operation ofIR illuminators 1206/1224, visible light illuminators 1210A-1210B/1226,and/or visible/NIR light camera 1204/1220, based on the detection anddetermination of the presence, type, and/or other attributes of objectsof interest in the surveillance scene. In some embodiments, the controlsignals may be generated based further on user-defined parameters, whichmay specify, for example, various illumination and recording operationsof the surveillance scene according to the type and/or other attributesof the detected objects.

For example, as a default setting, if the detected object is determinedto be a person, processor 1210 may control visible light illuminators1210A-1210B/1226 to track the person in a spotlight mode and optionallyrecord images of at least a portion of the scene with an appropriate oneof visible/NIR light cameras 1204/1220 (e.g., turn on and/or record whenthe person is within the FOV and turn off and/or stop recording when theperson leaves the FOV) based on the position and/or motion vectorassociated with the person. If the detected object is a vehicle or otherlarge objects, processor 1210 may control visible light illuminators1210A-1210B/1226 to illuminate the scene in a floodlight mode while theobject is in the scene and optionally record images of the scene withappropriate visible/NIR light cameras 1204/1220 based on the positionand/or motion vector associated with the object. If the detected objectis an animal or other non-spurious objects to be monitoredsurreptitiously, processor 1210 may control IR illuminators 1206/1224 toturn on while the object is in the scene and record visible/NIR,thermal, or blended images of the scene with an appropriate ones ofvisible/NIR light cameras 1204/1220 and thermal imager 1202 based on theposition and/or motion vector associated with the object. If thedetected object is a spurious object (e.g., spider webs, insects, tumbleweed, or other objects not of interest for surveillance purposes),processor 1210 may leave the illuminators and cameras off. In oneembodiment, processor 1210 may control visible light illuminators1210A-1210B/1226 to change the size of the beam angle (e.g., beam width,beam diameter) based on the size or the type of the detected object.

Various other associations between a detected object type andcorresponding illumination/monitoring operations may be implemented. Insome embodiments, processor 1210 may be further configured to allowusers to define such associations. For example, in some circumstances,it may be preferable to turn on IR illuminators 1206/1224 rather thanvisible light illuminators 1210A-1210B/1226, so that people can bemonitored without drawing their attention. In another example, ratherthan ignoring spurious objects (e.g., including objects that could notbe classified), it may be preferable to record thermal images or blended(e.g., high contrast, high resolution thermal images generated bythermal images with NIR or visible light images) images of the scene sothat the images may be reviewed for possible causes of detected spuriousobject motions (e.g., a person hiding behind a bush). In yet anotherexample, if more than one person or object is detected, it may bepreferable in some circumstances to track with a spotlight and/or recordeach person or object separately and individually. Users may define,customize, or otherwise configure these and other desired associationsbetween triggering object type and corresponding illumination/monitoringoperations, as well as other user-definable parameters such as the timeof day for activating certain illumination/monitoring operations. Suchassociations, definitions, customizations, or configurations may all bereferred herein as user-defined parameters. The user-defined parametersmay be stored in memory (e.g., in storage device 1214).

In some embodiments, processor 1210 may be configured to generateuser-viewable thermal images (e.g., thermograms) of a surveillance scene(e.g., scene 1230) captured by thermal imager 1202. Processor 1210 maybe configured to convert the thermal images using appropriate methodsand algorithms. In one embodiment, the radiometric data (e.g.,temperature data) contained in the pixels of the thermal images may beconverted into gray-scaled or color-scaled pixels to construct imagesthat can be viewed by a person. User-viewable thermal images mayoptionally include a legend or scale that indicates the approximatetemperature of corresponding pixel color and/or intensity. In anotherembodiment, processor 1210 may be configured to blend, superimpose,fuse, or otherwise combine the thermal images and visible/NIR lightimages (e.g., captured by visible/NIR light camera 1204/1220) togenerate user-viewable images having a higher definition and/or clarity.For example, processor 1210 may be configured to perform a resolutionand contrast enhancing fusion operation disclosed in U.S. patentapplication Ser. No. 13/105,765, filed May 11, 2011, which isincorporated herein by reference in its entirety. In very low lightsituations or complete darkness, such thermal or blended images mayprovide more useful information than actively illuminated NIR images.

In some embodiments, processor 1210 may generate control signals toactivate/deactivate or otherwise control operation of external devices.For example, processor 1210 may be configured to generate a controlsignal to operate a gate or a garage door based on a detection of avehicle and a determination of the position and/or motion vector of thevehicle. In another example, a security light 1236, a streetlight, orother similar lights and lamps in or near the surveillance scene may becontrolled by processor 1210. In such embodiments, user-definedparameters may further include user-defined associations between thedetected object type and operations of external devices.

In this regard, communication module 1212 may be configured to handle,manage, or otherwise facilitate wired and/or wireless communicationbetween camera system 1200 and an external device, as well as betweenvarious components of camera system 1200. For example, throughcommunication module 1212, processor 1210 may transmit control signalsto remote visible/NIR light camera 1220, an external surveillance camerasystem, a garage door opener, a security light, or other remotelylocated components of camera system 1200 or external devices.

In various embodiments, to handle, manage, or otherwise facilitatecommunication between camera system 1200 and an external device,communication module 1212 may support various interfaces, protocols, andstandards for home and building automation networking, such as the X10standard, the Building Automation and Control Networks (BACNet)protocol, the S-Bus protocol, the C-bus protocol, the CEBus protocol,the ONE-NET standard, and/or others.

Control signals to devices may be transmitted from communication module1212 directly to devices using such standards, or may be transmitted toa central controller (e.g., a conventional building control panel forbuilding/home automation) that relays and distributes the controlsignals to various devices under its control. For example, viacommunication module 1212, processor 1210 may transmit commands to abuilding access control (e.g., for opening, closing, locking, unlockingdoors and gates) and/or to a building lighting control.

In various embodiments, communication module 1212 may be furtherconfigured to support various interfaces, protocols, and standards forsurveillance cameras and systems, such as the ONVIF standard and/orothers. Thus, for example, camera system 1200 may control otherONVIF-compliant external cameras via communication module 1212, transmitcaptured or recorded images to an ONVIF-compliant central monitoringstation, transmit object detection information or other data generatedby processor 1210, and/or receive commands and configurations (e.g.,user-defined parameters) from an ONVIF-compliant computer.

In various embodiments, communication module 1212 may be furtherconfigured to more general wireless and/or wired networking interfaces,protocols, and standards. In one embodiment, communication module 1212may include a wireless communication component (e.g., based on the IEEE802.11 WiFi standards, the Bluetooth™ standard, the ZigBee™ standard, orother appropriate short range wireless communication standards), awireless broadband component (e.g., based on WiMax technologies), mobilecellular component, a wireless satellite component, or other appropriatewireless communication components. Communication module 1212 may includean antenna coupled thereto for wireless communication purposes. In oneembodiment, communication module 1212 may be configured to interfacewith a wired network via a wired communication component such as apower-line modem (e.g., supporting HomePlug™ standard), a DigitalSubscriber Line (DSL) modem, a Public Switched Telephone Network (PSTN)modem, an Ethernet interface, a cable modem, and/or other appropriatecomponents for wired communication. In some embodiments, communicationmodule 1211 may be configured for a proprietary wired communicationprotocols and interface, and/or for a proprietary wireless communicationprotocol and interface based on radio frequency (RF), microwavefrequency (MWF), infrared frequency (IRF), and/or other appropriatewireless transmission technologies.

Thus, for example, via wired or wireless connection, camera system 1200may control various external devices, transmit captured or recordedimages to an external monitoring and/or recorder device, transmit objectdetection information or other data generated by processor 1210, and/orreceive commands and configurations (e.g., user-defined parameters) froman external computer.

In various embodiments, camera system 1200 may comprise as many suchcommunication modules 1212 as desired for various applications of cameramonitoring system 1200. In other embodiments, communication module 1212may be integrated into or implemented as part of various othercomponents of camera system 1200. For example, thermal imager 1202,processor 1210, and remote visible/NIR light camera 1220 may eachcomprise a subcomponent that may be configured to perform the operationsof communication module 1212, and may communicate via wired and/orwireless connection without separate communication module 1212.

Storage device 1214 may include one or more memory devices orelectro-mechanical storage devices and associated logic (e.g.,implemented in hardware, software, or a combination of both) for storingand accessing data and information in the one or more memory orelectro-mechanical storage devices. The one or more memory orelectro-mechanical storage devices may include various types of volatileand non-volatile memories and storages, such as a hard disk drive, aflash memory, a RAM (Random Access Memory), an EEPROM(Electrically-Erasable Read-Only Memory), and other devices for storingdigital information.

In various embodiments, storage device 1214 may be configured to storeand access images captured by the various cameras and imagers of camerasystem 1200. In one embodiment, at least a part of storage device 1214may be implemented with a conventional DVR for storing and accessingvideo image data. Thus, for example, storage device 1214 may beconfigured to communicate, directly or via communication module 1212,with visible/NIR light cameras 1204/1220 and/or processor 1210 toreceive various raw and/or processed images of the surveillance scene,and record such images. For example, storage device 1214 may be utilizedto record visible/NIR light images of the surveillance scene captured byvisible/NIR light cameras 1204/1220, user-viewable thermal imagesconverted by processor 1210 from thermal images captured by thermalimager 1202, and/or blended thermal and NIR images generated byprocessor 1210. In this regard, storage device 1212 and/or processor1210 may be configured to compress and/or convert images intoappropriate format such as the various moving picture experts group(MPEG) format. In some embodiments, storage device 1214 may beimplemented locally with thermal imager 1202 and/or various componentsof camera system 1200. In other embodiments, storage device 1214 may beimplemented remotely and in communication with various components ofsystem 1200 (e.g., over network 1260 via communication module 1212, orotherwise). Mixed local and remote implementations are alsocontemplated.

In various embodiments, storage device 1214 may be utilized to storeother data and information generated and/or used by camera system 1200.For example, in some embodiments, processor 1210 may be configured toexecute software instructions stored on storage device 1214 and/or on amachine readable medium 193 (see FIG. 1) to perform all or part ofvarious methods, processes, or operations described herein. In anotherexample, the user-defined parameters may also be stored in storagedevice.

Miscellaneous components 1216 may include any other device or componentas may be desired for various application of camera system 1200. In someembodiments, miscellaneous components 1216 may include a globalpositioning system (GPS) receiver and/or an electronic compass. GPSreceiver and/or electronic compass 1216 may be implemented with anappropriate chipset or electronics module adapted for integration intosmall electronic devices to provide GPS receiver operations, electroniccompass operations, or both. GPS receiver and/or the electronic compassmay be utilized to automatically obtain geopositional informationrelating to the installed location of camera system 1200. Thegeopositional information may be used by processor 1210 and/orcommunication module 1212 to automatically construct positional mappinginformation, using appropriate techniques known in the art of computernetworking, for location-aware communication among multiple instances ofcamera system 1200, other surveillance cameras and systems, and otherexternal devices.

In some embodiments, miscellaneous components 1216 may include aphotocell for detecting the amount of ambient light. Such a photocellmay be used to determine whether or not active illumination may beneeded, as discussed above in connection with Visible/NIR light camera1204/1220.

In some embodiments, miscellaneous components 1216 may include a warninglight (e.g., a strobe light, a flashing light), a chime, a speaker withassociated circuitry for generating a tone, or other appropriate devicesthat may be used to generate an audible and/or visible alarm. Suchdevices may be used to alert, for example, an occupant of a premise thatan unusual event (e.g., a trespasser is detected) has occurred.

In some embodiments, miscellaneous components 1216 may include aportable power source such as a battery or a solar panel. Together withcommunication module 1212 configured for wireless communication, theportable power source may permit camera system 1200 to be convenientlyinstalled at various locations for surveillance, including locationswhere power lines and/or network cables cannot easily reach. Asdiscussed herein, camera system 1200 may permit power savings that maymake the portable power source a meaningful alternative to wired powersources.

In various embodiments, one or more components of camera system 1200 maybe combined and/or implemented or not, as desired or depending onapplication requirements. For example, processor 1210 may be combinedwith thermal imager 1202, communication module 1212, and/or storagedevice 1214. In another example, processor 1210 may be combined withthermal imager 1202 with only certain operations of processor 1210performed by circuitry (e.g., processor, logic device, microprocessor,or microcontroller) within thermal imager 1202. In another example,processor 1210 and/or storage device 1214 may be implemented usingappropriate components of a conventional DVR device, which may belocated remote from or co-located with other components of camera system1200 as desired for various applications of camera system 1200.

Therefore, various embodiments of smart surveillance camera system 1200may provide intelligent illumination and recording of a surveillancescene, by processing and analyzing thermal images of the surveillancescene captured by thermal imager 1202. Various embodiments of camerasystem 1200 may intelligently control various active illuminators (e.g.,IR illuminators 1206/1224, visible light illuminators 1210A-1210B/1226),cameras (e.g., visible/NIR light camera 1204/1220), and external devicesaccording to the type and/or other attributes of the detected objects.Various embodiments of camera system 1200 may also permit users tofurther define, customize, configure various intelligentillumination/monitoring operations according to the type and/or otherattributes of the detected objects.

In addition, camera system 1200 may reduce attraction of insects andspider webs by turning on illuminators intermittently only when needed,and even if spurious objects such as spider webs or insects are present,cameras do not constantly record meaningless images since spuriousobjects can be detected as such by capturing and analyzing thermalimages of the surveillance scene. As such, camera system 1200 maybeneficially reduce power consumption by illuminators and cameras, aswell as save time and effort wasted in reviewing long clips ofmeaningless video images.

FIG. 13 shows a front view of a smart surveillance camera system 1300implemented in accordance with an embodiment of the disclosure.Components of camera system 1300 may be implemented in the same orsimilar manner as the corresponding components of camera system 1200. Asthis example shows, camera system 1300 may include a plurality of IRilluminators 1306, disposed along a front edge thereof and aligned in acircular form. Such alignment of IR illuminators 1306 may permit a largenumber of IR illuminators to be placed on the front side surface ofcamera system 1300 and also create a large illumination area. IRilluminators 1306 may be implemented with VCSELs, which may providehigher energy efficiency compared with other types of IR light sources.

Visible light illuminators 1308 in this embodiment may include a largenumber of LED lights disposed throughout the front side surface ofcamera system 1300 except where a thermal imager 1302, a CMOS-basedvisible/NIR light camera 1304, and IR illuminators 1306 are located.Visible light illuminators 1308 may be aligned to direct beams of lightin specific directions, such that a moving spotlight may be created byselectively turning on, turning off, dimming, or brightening visiblelight illuminators 1308. Each one of visible light illuminators 1308 maybe aligned in a direction that is distinct from one another, oralternatively, two or more of visible light illuminators 1308 may bealigned in a same direction as a group. Similarly, a moving spotlightmay be created by selectively turning on, turning off, dimming, orbrightening each one of visible light illuminators 1308 individually oras a group. All or most of the plurality of visible light illuminators1308 may be turned on (e.g., when a control signal to operate in afloodlight mode is received from a processor and/or thermal imager 1302)to create a floodlight that may cover a large illumination area.

FIG. 14 shows a front view of a smart surveillance camera system 1400implemented in accordance with another embodiment of the disclosure.Components of camera system 1400 may be implemented in the same orsimilar manner as the corresponding components of camera system1200/1300. Camera system 1400 may include thermal imager 1402,CMOS-based visible/NIR light camera 1404, a plurality of VCSEL-based IRilluminators 1406, and a plurality of LED-based visible lightilluminators 1408, all of which may be disposed on the front sidesurface similar to camera system 1300. However, in this embodiment,visible light illuminators 1408 may be smaller in number compared withvisible light illuminators 1308, and may be positioned in a centralregion of the front side surface of camera system 1400. Further, ratherthan being fixed in direction, visible light illuminators 1408 mayinclude drive mechanisms 1418 (e.g., motors, actuators) that pan, tilt,or otherwise change the orientation of one or more (e.g., some,substantially all, or all) of visible light illuminators 1408. Thus, inthis embodiment, a tracking spotlight may be created using drivemechanisms 1418. Visible light illuminators 1408 may also provide anadjustable beam angle (i.e., diameter or width of a light beam), forexample, using adjustable reflectors, to increase or decreaseillumination area as desired for alternating between a spotlight and afloodlight.

FIG. 15 shows an example of smart surveillance camera system 1200implemented as a module 1500 that can be conveniently mounted, attached,or otherwise placed in various locations (e.g., on a ceiling, on a wall)in accordance with yet another embodiment of the disclosure. Module 1500may include a thermal imager 1502, a visible/NIR light camera 1504, IRilluminators 1506, visible light illuminators 1508, a processor 1510, acommunication module 1512, and a storage device 1514, any one of whichmay be implemented in the same or similar manner as the correspondingcomponents of camera system 1200/1300/1400 except where otherwise noted.

Module 1500 may also include a housing 1550 that permits module 1500 tobe mounted, attached, or otherwise installed conveniently at variouslocations, so that a network of smart surveillance camera systems 1200,for example, may be quickly and conveniently deployed. Module 1500 mayalso include a transparent cover 1551 disposed on housing 1550.Transparent cover 1551 may be configured to pass infrared and visiblelight through to infrared imaging module 1502 and visible/NIR lightcamera 1504, and may protect these and other components of module 1500from external elements (e.g., rain, debris).

Referring now to FIG. 16, a flowchart is illustrated of a process 1600to perform smart illumination and monitoring of a surveillance scene, inaccordance with an embodiment of the disclosure. For example, process1600 may be performed by various embodiments of camera system 1200. Itshould be appreciated that scene 1230, camera system 1200 and variouscomponents thereof are identified only for purposes of example, and thatany other suitable camera system may be utilized to perform all or partof process 1600.

At block 1602, thermal images (e.g., containing pixels with radiometricdata) of a surveillance scene may be captured by a thermal imager. Forexample, images of thermal radiation from scene 1230 within FOV 1205 maybe captured by thermal imager 1202 of FIG. 12. Because thermal imagers(e.g., thermal imager 1202) passively detect thermal radiation from thescene, active IR illumination is not required. Moreover, in contrast toactively illuminated images that are often washed out if an object istoo close to illuminators and too dimly lit if the object is not closeenough, thermal images may provide clear thermographic images of objectseven in complete darkness and even when obscured by fog or smoke.

The captured thermal images may be radiometrically calibrated thermalimages, and in some embodiments scale and/or perspective calibratedthermal images, as described above in connection with thermal imager1202. The captured thermal images may be received, for example, atprocessor 1210 that is communicatively coupled to thermal imager 1202.

At block 1604, various thermal image processing operations may beperformed on the captured thermal images. For example, one or more NUCprocesses may be performed on the captured thermal images to removenoise therein, for example, by using various NUC techniques disclosedherein. Various other image processing operations, such as conventionalsegmentation, filtering, transformation, or deconvolution operations,may also be performed as desired for various applications of process1600.

At block 1606, the processed thermal images may be further processedand/or analyzed to detect a presence of an object of interest, anddetermine one or more attributes associated with the detected object. Inone embodiment, regions of contiguous pixels having temperature valuesin a specific range may be detected from the radiometrically calibratedthermal images for detection of an object of interest. For example, thedetection operation may differentiate a region (or a “blob”) having asurface temperature distribution that is characteristic of a person, amotor vehicle, or an animal. The thermal images and the blob detectedtherein may be further processed and/or analyzed, for example, byperforming various filtering operations and analyzing the size, shape,and/or thermal characteristics of the blob, to ascertain the detectionof the object.

In another embodiment, the thermal images may be analyzed to detect oneor more candidate foreground objects, for example, using backgroundmodeling techniques, edge detection techniques, or other foregroundobject detection techniques suitable for use with thermal images. Theradiometric properties (e.g., surface temperature distribution) of thecandidate objects may then be analyzed to determine whether theycorrespond to those of an object of interest (e.g., a person, a vehicle,an animal). For example, a spider web hanging in front of a thermalimager may initially be detected as a candidate foreground object, butits radiometric properties may then quickly reveal that it does not havea surface temperature distribution characteristic of an object ofinterest. As this example shows, object detection using the thermalimages may be less susceptible to false detection of spurious objects(e.g., close up and/or washed out images of a spider web or a moth)compared with object detection techniques using actively illuminatedvisible or NIR light images. The size and shape of the candidate objectsmay also be analyzed, so that the detection may be ascertained based onthe size, the shape, and the radiometric properties of the detectedcandidates.

In one aspect of this embodiment, background modeling techniques may beused to detect objects in the scene. Because the background (e.g., anempty surveillance scene) rarely changes and because thermal images aregenerally insensitive to changing lighting conditions, a backgroundmodel (e.g., pixels that belong to a background) may be constructed withhigh accuracy, and a region of pixels different from the background(also referred to as a “region of interest”) may easily be distinguishedas a candidate foreground object. As described above, the radiometricproperties of such a region of interest (ROI) may then be analyzed tofurther ascertain whether the detected ROI likely represent an object ofinterest or not.

Various attributes associated with the detected object of interest maybe determined through further analysis and processing and/or during theprocessing and analysis performed for object detection. For example, thetype of the detected object may be determined, by analyzing the size,the shape, and/or the radiometric properties and, in some embodimentscomparing them with profiles or signatures of reference objects of acertain type of interest. In various embodiments, the position of thedetected object may be determined by translating the pixel coordinatesof the detected objects in the thermal images into approximate locationin the surveillance scene. In some embodiments, the motion vector (i.e.,the speed and direction of movement) associated with the detectedobjects may also be determined from the thermal images using appropriatetechniques in video and image analytics.

In various embodiments, the various processing and analysis operationsdescribed for block 1606 may be omitted or included, and may beperformed in any other order as appropriate for detecting objects anddetermining associated attributes. For example, in some embodiments,detecting a warm “blob” in the thermal images may be sufficient todetect an object of interest in a scene, whereas in other embodimentsvarious thermal image analytics may be performed in combination toincrease the accuracy of the detection. Other appropriate techniques fordetecting objects in thermal images may also be utilized for block 1606.

At block 1608, various illuminators (e.g., IR illuminators 1206/1224and/or visible light illuminators 1210A-1210B/1226), cameras(visible/NIR light camera 1204/1220), and/or storage devices (e.g., DVRsor other devices) may be activated and/or otherwise controlled based onthe presence and the type of an object of interest as determined byanalyzing the thermal images of the surveillance scene. For example, asdescribed above with respect to FIG. 12, visible light illuminators maybe activated and controlled to illuminate an object in a trackingspotlight mode; visible light illuminators may be activated toilluminate an object in a floodlight mode; IR illuminators may beactivated to provide active IR illumination for NIR image recording;visible/NIR light cameras, along with a DVR, may be activated to recordimages of the surveillance scene; and/or visible/NIR light cameras maybe panned, tilted, or zoomed to track an object. Based on the positionand/or motion vector of the detected object, cameras and illuminatorsmay be activated, deactivated, or otherwise controlled depending ontheir locations.

The captured or recorded images of the surveillance scene may includevisible/NIR light images, user-viewable thermal images, and/or blendedimages (e.g., by fusing images captured by a visible/NIR camera withthermal images captured by a thermal imager). In this regard, process1600 may further include generating user-viewable thermal images of thesurveillance scene, and/or combining the thermal images and thevisible/NIR light images to generate blended images having a higherdefinition and/or clarity, as described above in connection withprocessor 1210 of FIG. 12.

As also discussed above, users may further define, customize, orotherwise configure the association between such operations and thetriggering object types. In this regard, user-defined parameters may bereceived from a user. For example, files or data packets containing theuser-defined parameters may be received from an external computer of auser. In another example, commands and/or inputs from a user may bereceived through a control panel (e.g., including keyboard, pointingdevice, physical buttons, sliders, dials, or other actuated mechanisms)or graphical user interface (GUI) provided on a camera system. Thereceived files, data, or inputs may be compiled, processed, otherwisemanaged to update the association between triggering object types andcorresponding operations.

In various embodiments, other actions or operations may be performedbased on the thermal image analysis. For example, a machine-operatedgate or a garage door may be opened or closed based on a detection of avehicle that is near or approaching the gate or door (e.g., asdetermined by the position and/or the motion vector). Similarly, asecurity light, a streetlight, a porch light, or other similar lightsand lamps may be controlled based on the type, the position, and/or themotion vector of objects. In another example, alarms may be triggered ifan exceptional event occurs (e.g., a person crossing a virtualboundary).

In this regard, process 1600 may further include communicating withexternal devices. For example, process 1600 may include transmittingcontrol signals to external devices such as an external camera, abuilding access controller, or a building lighting controller. In otherexamples, process 1600 may include transmitting captured or recordedimages to an external monitoring and/or recorder device, transmittingobject detection information or other data generated by variousoperations of process 1600, and/or receiving commands and configurations(e.g., user-defined parameters) from an external computer.

Therefore, all or part of process 1600 may be performed to intelligentlycontrol illumination and monitoring of a surveillance scene, usingthermal images of the scene. Appropriate illuminators, cameras, storagedevices, and/or other external devices may advantageously be controlledaccording to the type and/or other attributes of the detected objects,where users may further define or customize corresponding illuminationand/or recording operations. Because active illuminators can be turnedon intermittently only when needed or desired, accumulation of spiderwebs or insects may be mitigated and power consumption may be reduced.Moreover, even if spider webs or other spurious objects do build up nearcamera lenses, thermal image analysis operations in process 1600 permita more robust detection that can discern spurious objects, therebypreventing recording of meaningless surveillance images.

Where applicable, various embodiments provided by the present disclosurecan be implemented using hardware, software, or combinations of hardwareand software. Also where applicable, the various hardware componentsand/or software components set forth herein can be combined intocomposite components comprising software, hardware, and/or both withoutdeparting from the spirit of the present disclosure. Where applicable,the various hardware components and/or software components set forthherein can be separated into sub-components comprising software,hardware, or both without departing from the spirit of the presentdisclosure. In addition, where applicable, it is contemplated thatsoftware components can be implemented as hardware components, andvice-versa.

Software in accordance with the present disclosure, such asnon-transitory instructions, program code, and/or data, can be stored onone or more non-transitory machine readable mediums. It is alsocontemplated that software identified herein can be implemented usingone or more general purpose or specific purpose computers and/orcomputer systems, networked and/or otherwise. Where applicable, theordering of various steps described herein can be changed, combined intocomposite steps, and/or separated into sub-steps to provide featuresdescribed herein.

Embodiments described above illustrate but do not limit the invention.It should also be understood that numerous modifications and variationsare possible in accordance with the principles of the invention.Accordingly, the scope of the invention is defined only by the followingclaims.

What is claimed is:
 1. A system comprising: a thermal imager comprisinga focal plane array (FPA) configured to capture thermal images of ascene; a light source configured to illuminate the scene; a cameraconfigured to capture additional images of the scene; and a processorconfigured to; analyze the thermal images to determine an attributeassociated with an object in the scene, and selectively operate thelight source and the camera based on the attribute of the object.
 2. Thesystem of claim 1, wherein the light source is a visible light source,the system further comprising an infrared (IR) tight source, wherein theprocessor is configured to selectively operate either the visible lightsource or the IR light source based on the attribute of the object. 3.The system of claim 1, wherein: the attribute is a position of theobject in the scene; and the processor is configured to selectivelydirect the light source toward the object in response to a change of theposition of the object in the scene.
 4. The system of claim 1, wherein:the attribute is a size of the object in the scene; and the processor isconfigured to selectively adjust a beam width of the light source basedon the size of the object in the scene.
 5. The system of claim 1,wherein: the camera is a non-thermal camera; and the light source isconfigured to provide illumination over at least a portion of a spectrumassociated with the additional images.
 6. The system of claim 5, whereinthe spectrum comprises at least a portion of a near infrared (NIR)spectrum.
 7. The system of claim 6, wherein the processor is configuredto combine the thermal images and the additional images to generateblended images of the scene.
 8. The system of claim 1, wherein theprocessor is configured to selectively start and stop a recording of thethermal images and/or the additional images based on the attribute ofthe object, the system further comprising a storage device positioned ata remote location relative to the thermal imager and configured torecord the thermal images and/or the additional images in response tothe processor.
 9. The system of claim 1, wherein the processor isconfigured to selectively start and stop a recording of the thermalimages and/or the additional images based on the attribute of theobject, wherein the camera is a first camera having a first field ofview (FOV), the system further comprising a second camera configured tocapture other additional images of the scene, and having a second FOV,wherein: the attribute is a position of the object, and the processor isconfigured to: determine whether to record the additional images and/orthe other additional images based on the position of the object relativeto the first and second FOVs, and selectively start and stop a recordingof the additional images and/or the other additional images based on thedetermination.
 10. The system of claim 1, wherein the processor isfurther configured to selectively operate an external device based onthe attribute of the object.
 11. The system of claim 1, wherein: thethermal images are unblurred thermal images of the scene; the thermalimager is configured to capture intentionally blurred thermal images ofthe scene; and the processor is configured to determine a plurality ofnon-uniform correction (NUC) terms based on the intentionally blurredthermal images and apply the NUC terms to the unblurred thermal imagesto remove noise from the unblurred thermal images.
 12. A methodcomprising: capturing, at a focal plane array (FPA) of a thermal imager,thermal images of a scene; analyzing the thermal images to determine anattribute associated with an object in the scene; and selectivelyoperating a light source and a camera based on the attribute of theobject, wherein: the light source is configured to illuminate the scene,and the camera is configured to capture additional images of the scene.13. The method of claim 12, wherein the light source is a visible lightsource, the method further comprising selectively operating either thevisible light source or an infrared (IR) light source based on theattribute of the object, wherein the IR light source is configured toilluminate the scene.
 14. The method of claim 12, wherein: the attributeis a position of the object in the scene; and the selectively operatingthe light source comprises selectively directing the light source towardthe object in response to a change of the position of the object in thescene.
 15. The method of claim 12, wherein: the attribute is a size ofthe object in the scene; and the selectively operating the light sourcecomprises selectively adjusting a beam width of the light source basedon the size of the object in the scene.
 16. The method of claim 12,further comprising combining the thermal images and the additionalimages to generate blended images of the scene, wherein: the camera is anon-thermal camera, and the light source is configured to provideillumination over at least a portion a spectrum associated with theadditional images.
 17. The method of claim 12, wherein the selectivelyoperating the camera comprises selectively starting and stopping arecording of the thermal images and/or the additional images based onthe attribute of the object, wherein the selectively starting andstopping a recording comprises recording the thermal images and/or theadditional images to a storage device positioned at a remote locationrelative to the thermal imager.
 18. The method of claim 12, wherein: theselectively operating the camera comprises selectively starting andstopping a recording of the thermal images and/or the additional imagesbased on the attribute of the object; the camera is a first camerahaving a first field of view (FOV); the attribute is a position of theobject; and the selectively starting and stopping a recording comprises:determining whether to record the additional images and/or otheradditional images of the scene captured by a second camera having asecond FOV, based on the position of the object relative to the firstand second FOVs, and selectively starting and stopping a recording ofthe additional images and/or the other additional images based on thedetermination.
 19. The method of claim 12, further comprisingselectively operating an external device based on the attribute of theobject.
 20. The method of claim 12, wherein the thermal images areunblurred thermal images, the method further comprising: capturingintentionally blurred thermal images of the scene; determining aplurality of non-uniform correction (NUC) terms based on theintentionally blurred thermal images; and applying the NUC terms to theunblurred thermal images to remove noise from the unblurred thermalimages.